diff --git a/zhixing-server/src/zhixing_server/modules/sector_radar/application/read.py b/zhixing-server/src/zhixing_server/modules/sector_radar/application/read.py
index 0313502..4c69780 100644
--- a/zhixing-server/src/zhixing_server/modules/sector_radar/application/read.py
+++ b/zhixing-server/src/zhixing_server/modules/sector_radar/application/read.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from dataclasses import dataclass
 from datetime import date
 from enum import StrEnum
@@ -20,11 +21,13 @@ from ..domain.models import (
     RankSide,
     SectorType,
 )
-from ..domain.persistence import SectorRadarRepository
+from ..domain.persistence import SectorRadarRepository, StockMembershipEntry
 from ..domain.ranking import select_percentile_side, select_rank_change_side
 
 ReadStatus = Literal["success", "no_data"]
 
+STOCK_SECTOR_CONCEPT_LIMIT = 20
+
 
 class RadarView(StrEnum):
     """Supported ranking projections at the HTTP boundary."""
@@ -101,6 +104,50 @@ class RankingPage:
     total: int
 
 
+@dataclass(frozen=True, slots=True)
+class SectorRef:
+    """Public identity of one sector that claimed a stock."""
+
+    code: str
+    name: str
+
+
+@dataclass(frozen=True, slots=True)
+class StockSectorQuery:
+    """Validated application query for one stock's point-in-time membership."""
+
+    trade_date: date
+    ts_code: str
+    concept_limit: int = STOCK_SECTOR_CONCEPT_LIMIT
+
+    def __post_init__(self) -> None:
+        """Reject empty stock codes and non-positive concept limits."""
+
+        if not self.ts_code.strip():
+            raise ValueError("ts_code must not be empty")
+        if len(self.ts_code) > 12:
+            raise ValueError("ts_code must not exceed 12 characters")
+        if self.concept_limit < 1:
+            raise ValueError("concept_limit must be at least 1")
+
+
+@dataclass(frozen=True, slots=True)
+class StockSectorMembership:
+    """One stock's industries and concepts as observed on one snapshot date.
+
+    ``trade_date`` is the actual membership snapshot date, which is the newest
+    successful build at or before the requested date; it must never be
+    substituted with a newer snapshot.
+    """
+
+    status: ReadStatus
+    query: StockSectorQuery
+    trade_date: date | None
+    industries: tuple[SectorRef, ...]
+    concepts: tuple[SectorRef, ...]
+    concept_total: int
+
+
 _METRIC_DEFINITIONS = {
     MetricKind.AMOUNT: RadarMetricDefinition(
         metric_kind=MetricKind.AMOUNT,
@@ -212,6 +259,48 @@ class ReadSectorRadar:
             total=len(searched),
         )
 
+    def stock_membership(self, query: StockSectorQuery) -> StockSectorMembership:
+        """Return one stock's sectors from the strict last-good build snapshot."""
+
+        publication = self.repository.get_last_good_publication(query.trade_date)
+        if publication is None:
+            return StockSectorMembership(
+                status="no_data",
+                query=query,
+                trade_date=None,
+                industries=(),
+                concepts=(),
+                concept_total=0,
+            )
+        entries = self.repository.load_stock_memberships(
+            publication.target_trade_date, query.ts_code
+        )
+        industries = _sector_refs(
+            entry for entry in entries if entry.sector_type is SectorType.INDUSTRY
+        )
+        concepts = _sector_refs(
+            entry for entry in entries if entry.sector_type is SectorType.CONCEPT
+        )
+        return StockSectorMembership(
+            status="success",
+            query=query,
+            trade_date=publication.target_trade_date,
+            industries=industries,
+            concepts=concepts[: query.concept_limit],
+            concept_total=len(concepts),
+        )
+
+
+def _sector_refs(entries: Iterator[StockMembershipEntry]) -> tuple[SectorRef, ...]:
+    """Project membership entries into ordered public sector references."""
+
+    return tuple(
+        sorted(
+            (SectorRef(code=entry.sector_code, name=entry.sector_name) for entry in entries),
+            key=lambda ref: (ref.code, ref.name),
+        )
+    )
+
 
 __all__ = [
     "RadarDateIndex",
@@ -220,4 +309,8 @@ __all__ = [
     "RadarView",
     "RankingPage",
     "ReadSectorRadar",
+    "SectorRef",
+    "StockSectorMembership",
+    "StockSectorQuery",
+    "STOCK_SECTOR_CONCEPT_LIMIT",
 ]
diff --git a/zhixing-server/src/zhixing_server/modules/sector_radar/domain/persistence.py b/zhixing-server/src/zhixing_server/modules/sector_radar/domain/persistence.py
index 1c83b82..df20cb6 100644
--- a/zhixing-server/src/zhixing_server/modules/sector_radar/domain/persistence.py
+++ b/zhixing-server/src/zhixing_server/modules/sector_radar/domain/persistence.py
@@ -65,6 +65,22 @@ class MembershipRecord:
         return self.stock_code if self.stock_code is not None else "__membership_unknown__"
 
 
+@dataclass(frozen=True, slots=True)
+class StockMembershipEntry:
+    """One sector that claimed a stock on exactly one snapshot trade date."""
+
+    trade_date: date
+    sector_type: SectorType
+    sector_code: str
+    sector_name: str
+
+    def __post_init__(self) -> None:
+        """Reject empty sector identity fields."""
+
+        if not self.sector_code.strip() or not self.sector_name.strip():
+            raise ValueError("membership sector identity fields must not be empty")
+
+
 @dataclass(frozen=True, slots=True)
 class StockFactRecord:
     """One normalized stock fact revision with all contributing raw snapshots."""
@@ -197,6 +213,10 @@ class SectorRadarRepository(Protocol):
 
     def save_memberships(self, records: Iterable[MembershipRecord]) -> WriteCounts: ...
 
+    def load_stock_memberships(
+        self, trade_date: date, stock_code: str
+    ) -> Sequence[StockMembershipEntry]: ...
+
     def save_stock_facts(self, records: Iterable[StockFactRecord]) -> WriteCounts: ...
 
     def save_daily_aggregates(self, records: Iterable[DailyAggregateRecord]) -> WriteCounts: ...
diff --git a/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/memory.py b/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/memory.py
index 903f21e..1d5ee0d 100644
--- a/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/memory.py
+++ b/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/memory.py
@@ -15,6 +15,7 @@ from ..domain.persistence import (
     PublicationSourceRecord,
     RankingRecord,
     StockFactRecord,
+    StockMembershipEntry,
     WriteCounts,
 )
 from ..domain.source import SourceSnapshot
@@ -115,6 +116,27 @@ class InMemorySectorRadarRepository:
             ),
         )
 
+    def load_stock_memberships(
+        self, trade_date: date, stock_code: str
+    ) -> Sequence[StockMembershipEntry]:
+        """Return available sectors that claimed one stock on one snapshot date."""
+
+        return tuple(
+            StockMembershipEntry(
+                trade_date=record.trade_date,
+                sector_type=record.sector_type,
+                sector_code=record.sector_code,
+                sector_name=record.sector_name,
+            )
+            for record in sorted(
+                self.memberships.values(),
+                key=lambda item: (item.sector_type, item.sector_code),
+            )
+            if record.trade_date == trade_date
+            and record.stock_code == stock_code
+            and record.status.value == "available"
+        )
+
     def save_stock_facts(self, records: Iterable[StockFactRecord]) -> WriteCounts:
         """Insert normalized fact revisions idempotently."""
 
diff --git a/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/postgres.py b/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/postgres.py
index 1b5be9e..6508fd1 100644
--- a/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/postgres.py
+++ b/zhixing-server/src/zhixing_server/modules/sector_radar/infrastructure/postgres.py
@@ -31,6 +31,7 @@ from ..domain.persistence import (
     PublicationSourceRecord,
     RankingRecord,
     StockFactRecord,
+    StockMembershipEntry,
     WriteCounts,
 )
 from ..domain.source import SourceSnapshot
@@ -283,6 +284,32 @@ class PostgresSectorRadarRepository:
             rows,
         )
 
+    def load_stock_memberships(
+        self, trade_date: date, stock_code: str
+    ) -> Sequence[StockMembershipEntry]:
+        """Load every sector that claimed one stock on exactly one snapshot date."""
+
+        with self._connection() as connection:
+            rows = connection.execute(
+                """
+                SELECT trade_date, sector_type, sector_code, sector_name
+                FROM sector_radar_membership
+                WHERE trade_date = %s AND stock_code = %s
+                  AND membership_status = 'available'
+                ORDER BY sector_type, sector_code
+                """,
+                (trade_date, stock_code),
+            ).fetchall()
+        return tuple(
+            StockMembershipEntry(
+                trade_date=row[0],
+                sector_type=SectorType(row[1]),
+                sector_code=row[2],
+                sector_name=row[3],
+            )
+            for row in rows
+        )
+
     def save_stock_facts(self, records: Iterable[StockFactRecord]) -> WriteCounts:
         """COPY normalized stock facts while preserving contributing source ids."""
 
diff --git a/zhixing-server/src/zhixing_server/modules/sector_radar/presentation/http.py b/zhixing-server/src/zhixing_server/modules/sector_radar/presentation/http.py
index 10c9892..bd4ac85 100644
--- a/zhixing-server/src/zhixing_server/modules/sector_radar/presentation/http.py
+++ b/zhixing-server/src/zhixing_server/modules/sector_radar/presentation/http.py
@@ -8,17 +8,21 @@ from datetime import date, datetime
 from decimal import Decimal
 from typing import Annotated, Literal
 
-from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi import APIRouter, Depends, HTTPException, Path, Query
 from pydantic import BaseModel, Field
 
 from ....bootstrap.config import Settings, get_settings
 from ..application.read import (
+    STOCK_SECTOR_CONCEPT_LIMIT,
     RadarDateIndex,
     RadarMetricDefinition,
     RadarQuery,
     RadarView,
     RankingPage,
     ReadSectorRadar,
+    SectorRef,
+    StockSectorMembership,
+    StockSectorQuery,
 )
 from ..domain.models import (
     MetricKind,
@@ -122,6 +126,29 @@ class RadarRankingsResponse(BaseModel):
     rows: list[RadarRankingRowResponse] = Field(default_factory=_empty_ranking_rows)
 
 
+class SectorRefResponse(BaseModel):
+    """Public identity of one sector that claimed a stock."""
+
+    code: str
+    name: str
+
+
+class StockSectorMembershipResponse(BaseModel):
+    """One stock's point-in-time industries and concepts from last-good build.
+
+    ``trade_date`` is the actual membership snapshot date, never a newer one.
+    """
+
+    status: Literal["success", "no_data"]
+    ts_code: str
+    requested_trade_date: date
+    trade_date: date | None
+    industries: list[SectorRefResponse] = Field(default_factory=list)
+    concepts: list[SectorRefResponse] = Field(default_factory=list)
+    concept_total: int = Field(ge=0)
+    concept_limit: int = Field(ge=1, le=100)
+
+
 def get_sector_radar_reader(
     settings: Annotated[Settings, Depends(get_settings)],
 ) -> ReadSectorRadar:
@@ -196,6 +223,28 @@ def get_sector_radar_rankings(
         raise _storage_error() from exc
 
 
+@sector_radar_router.get(
+    "/stocks/{ts_code}/membership", response_model=StockSectorMembershipResponse
+)
+def get_stock_sector_membership(
+    reader: Annotated[ReadSectorRadar, Depends(get_sector_radar_reader)],
+    ts_code: Annotated[str, Path(min_length=1, max_length=12)],
+    trade_date: date,
+    concept_limit: Annotated[int, Query(ge=1, le=100)] = STOCK_SECTOR_CONCEPT_LIMIT,
+) -> StockSectorMembershipResponse:
+    """Return one stock's industries and concepts from the last-good snapshot."""
+
+    query = StockSectorQuery(
+        trade_date=trade_date,
+        ts_code=ts_code.strip(),
+        concept_limit=concept_limit,
+    )
+    try:
+        return _stock_membership_response(reader.stock_membership(query))
+    except SectorRadarRepositoryError as exc:
+        raise _storage_error() from exc
+
+
 def _dates_response(index: RadarDateIndex) -> RadarDatesResponse:
     return RadarDatesResponse(
         status=index.status,
@@ -231,6 +280,25 @@ def _rankings_response(page: RankingPage) -> RadarRankingsResponse:
     )
 
 
+def _stock_membership_response(
+    membership: StockSectorMembership,
+) -> StockSectorMembershipResponse:
+    return StockSectorMembershipResponse(
+        status=membership.status,
+        ts_code=membership.query.ts_code,
+        requested_trade_date=membership.query.trade_date,
+        trade_date=membership.trade_date,
+        industries=[_sector_ref_response(ref) for ref in membership.industries],
+        concepts=[_sector_ref_response(ref) for ref in membership.concepts],
+        concept_total=membership.concept_total,
+        concept_limit=membership.query.concept_limit,
+    )
+
+
+def _sector_ref_response(ref: SectorRef) -> SectorRefResponse:
+    return SectorRefResponse(code=ref.code, name=ref.name)
+
+
 def _publication_response(publication: RadarPublication) -> RadarPublicationResponse:
     return RadarPublicationResponse(
         publication_id=publication.publication_id,
@@ -297,6 +365,7 @@ def _storage_error() -> HTTPException:
 __all__ = [
     "RadarDatesResponse",
     "RadarRankingsResponse",
+    "StockSectorMembershipResponse",
     "get_sector_radar_reader",
     "sector_radar_router",
 ]
diff --git a/zhixing-server/tests/test_sector_radar_http.py b/zhixing-server/tests/test_sector_radar_http.py
index 2aa7ee9..491078c 100644
--- a/zhixing-server/tests/test_sector_radar_http.py
+++ b/zhixing-server/tests/test_sector_radar_http.py
@@ -13,6 +13,9 @@ from zhixing_server.modules.sector_radar.application.read import (
     RadarQuery,
     RadarView,
     RankingPage,
+    SectorRef,
+    StockSectorMembership,
+    StockSectorQuery,
 )
 from zhixing_server.modules.sector_radar.domain.metrics import AmountNetStrategy
 from zhixing_server.modules.sector_radar.domain.models import (
@@ -87,7 +90,9 @@ def _ranking() -> RankedMetric:
 class FakeReader:
     def __init__(self, *, no_data: bool = False, fail: bool = False) -> None:
         self.fail = fail
+        self.no_data = no_data
         self.last_query: RadarQuery | None = None
+        self.last_membership_query: StockSectorQuery | None = None
         success = _publication("publication-success", PublicationStatus.SUCCESS)
         current = _publication(
             "publication-partial",
@@ -125,6 +130,32 @@ class FakeReader:
         self.last_query = query
         return replace(self.page, query=query)
 
+    def stock_membership(self, query: StockSectorQuery) -> StockSectorMembership:
+        if self.fail:
+            raise SectorRadarRepositoryError("private database detail")
+        self.last_membership_query = query
+        if self.no_data:
+            return StockSectorMembership(
+                status="no_data",
+                query=query,
+                trade_date=None,
+                industries=(),
+                concepts=(),
+                concept_total=0,
+            )
+        return StockSectorMembership(
+            status="success",
+            query=query,
+            trade_date=TARGET_DATE,
+            industries=(SectorRef(code="BK0901.DC", name="银行"),),
+            concepts=(
+                SectorRef(code="BK0001.DC", name="机器人"),
+                SectorRef(code="BK0002.DC", name="人工智能"),
+                SectorRef(code="BK0003.DC", name="数字经济"),
+            ),
+            concept_total=3,
+        )
+
 
 def _client(reader: FakeReader) -> TestClient:
     application = create_app()
@@ -228,3 +259,78 @@ def test_repository_error_maps_to_redacted_503() -> None:
         }
     }
     assert "private database detail" not in response.text
+
+
+def test_stock_membership_maps_industries_and_concepts() -> None:
+    reader = FakeReader()
+    response = _client(reader).get(
+        "/api/v1/sector-radar/stocks/000001.SZ/membership",
+        params={"trade_date": "2026-08-28"},
+    )
+
+    assert response.status_code == 200
+    assert reader.last_membership_query == StockSectorQuery(
+        trade_date=TARGET_DATE,
+        ts_code="000001.SZ",
+    )
+    payload = response.json()
+    assert payload["status"] == "success"
+    assert payload["ts_code"] == "000001.SZ"
+    assert payload["requested_trade_date"] == "2026-08-28"
+    assert payload["trade_date"] == "2026-08-28"
+    assert payload["industries"] == [{"code": "BK0901.DC", "name": "银行"}]
+    assert payload["concept_total"] == 3
+    assert payload["concept_limit"] == 20
+    assert [concept["code"] for concept in payload["concepts"]] == [
+        "BK0001.DC",
+        "BK0002.DC",
+        "BK0003.DC",
+    ]
+
+
+def test_stock_membership_no_data_is_a_stable_200_response() -> None:
+    response = _client(FakeReader(no_data=True)).get(
+        "/api/v1/sector-radar/stocks/000001.SZ/membership",
+        params={"trade_date": "2026-08-28"},
+    )
+
+    assert response.status_code == 200
+    payload = response.json()
+    assert payload["status"] == "no_data"
+    assert payload["trade_date"] is None
+    assert payload["industries"] == []
+    assert payload["concepts"] == []
+    assert payload["concept_total"] == 0
+
+
+def test_stock_membership_rejects_invalid_query_values() -> None:
+    client = _client(FakeReader())
+
+    missing_date = client.get("/api/v1/sector-radar/stocks/000001.SZ/membership")
+    bad_limit = client.get(
+        "/api/v1/sector-radar/stocks/000001.SZ/membership",
+        params={"trade_date": "2026-08-28", "concept_limit": 0},
+    )
+    over_limit = client.get(
+        "/api/v1/sector-radar/stocks/000001.SZ/membership",
+        params={"trade_date": "2026-08-28", "concept_limit": 101},
+    )
+    empty_code = client.get(
+        "/api/v1/sector-radar/stocks//membership", params={"trade_date": "2026-08-28"}
+    )
+
+    assert missing_date.status_code == 422
+    assert bad_limit.status_code == 422
+    assert over_limit.status_code == 422
+    assert empty_code.status_code in (404, 422)
+
+
+def test_stock_membership_repository_error_maps_to_redacted_503() -> None:
+    response = _client(FakeReader(fail=True)).get(
+        "/api/v1/sector-radar/stocks/000001.SZ/membership",
+        params={"trade_date": "2026-08-28"},
+    )
+
+    assert response.status_code == 503
+    assert response.json()["detail"]["code"] == "sector_radar_storage_unavailable"
+    assert "private database detail" not in response.text
diff --git a/zhixing-server/tests/unit/sector_radar/test_read.py b/zhixing-server/tests/unit/sector_radar/test_read.py
index c071e56..c789afc 100644
--- a/zhixing-server/tests/unit/sector_radar/test_read.py
+++ b/zhixing-server/tests/unit/sector_radar/test_read.py
@@ -2,10 +2,14 @@ from dataclasses import replace
 from datetime import UTC, date, datetime, timedelta
 from decimal import Decimal
 
+import pytest
+
 from zhixing_server.modules.sector_radar.application.read import (
     RadarQuery,
     RadarView,
     ReadSectorRadar,
+    SectorRef,
+    StockSectorQuery,
 )
 from zhixing_server.modules.sector_radar.domain.metrics import AmountNetStrategy
 from zhixing_server.modules.sector_radar.domain.models import (
@@ -20,7 +24,10 @@ from zhixing_server.modules.sector_radar.domain.models import (
     RankSide,
     SectorType,
 )
-from zhixing_server.modules.sector_radar.domain.persistence import RankingRecord
+from zhixing_server.modules.sector_radar.domain.persistence import (
+    MembershipRecord,
+    RankingRecord,
+)
 from zhixing_server.modules.sector_radar.domain.ranking import rank_metric_observations
 from zhixing_server.modules.sector_radar.infrastructure.memory import (
     InMemorySectorRadarRepository,
@@ -187,3 +194,124 @@ def test_latest_partial_attempt_is_visible_but_does_not_replace_last_good() -> N
     assert index.last_good is not None
     assert index.last_good.publication_id == "publication-success"
     assert index.available_dates == (TARGET_DATE,)
+
+
+def _membership_record(
+    stock_code: str,
+    sector_type: SectorType,
+    sector_code: str,
+    sector_name: str,
+    *,
+    trade_date: date = TARGET_DATE,
+) -> MembershipRecord:
+    return MembershipRecord(
+        source_snapshot_id="b" * 64,
+        trade_date=trade_date,
+        sector_type=sector_type,
+        sector_code=sector_code,
+        sector_name=sector_name,
+        stock_code=stock_code,
+        stock_name="测试股票",
+    )
+
+
+def _membership_repository() -> InMemorySectorRadarRepository:
+    repository = _published_repository()
+    repository.save_memberships(
+        (
+            _membership_record("000001.SZ", SectorType.INDUSTRY, "BK0902.DC", "房地产"),
+            _membership_record("000001.SZ", SectorType.CONCEPT, "BK0003.DC", "数字经济"),
+            _membership_record("000001.SZ", SectorType.CONCEPT, "BK0001.DC", "机器人"),
+            _membership_record("000001.SZ", SectorType.CONCEPT, "BK0002.DC", "人工智能"),
+            _membership_record("000002.SZ", SectorType.INDUSTRY, "BK0901.DC", "银行"),
+        )
+    )
+    return repository
+
+
+def test_stock_membership_groups_types_and_orders_by_sector_code() -> None:
+    reader = ReadSectorRadar(_membership_repository())
+
+    membership = reader.stock_membership(
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="000001.SZ")
+    )
+
+    assert membership.status == "success"
+    assert membership.trade_date == TARGET_DATE
+    assert membership.industries == (SectorRef(code="BK0902.DC", name="房地产"),)
+    assert [ref.code for ref in membership.concepts] == [
+        "BK0001.DC",
+        "BK0002.DC",
+        "BK0003.DC",
+    ]
+    assert membership.concept_total == 3
+    other = reader.stock_membership(StockSectorQuery(trade_date=TARGET_DATE, ts_code="000002.SZ"))
+    assert other.industries == (SectorRef(code="BK0901.DC", name="银行"),)
+    assert other.concepts == ()
+    assert other.concept_total == 0
+
+
+def test_stock_membership_truncates_concepts_with_total_preserved() -> None:
+    reader = ReadSectorRadar(_membership_repository())
+
+    membership = reader.stock_membership(
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="000001.SZ", concept_limit=2)
+    )
+
+    assert [ref.code for ref in membership.concepts] == ["BK0001.DC", "BK0002.DC"]
+    assert membership.concept_total == 3
+
+
+def test_stock_membership_uses_newest_build_at_or_before_requested_date() -> None:
+    repository = _membership_repository()
+    earlier = _running("publication-earlier", TARGET_DATE - timedelta(days=1))
+    repository.create_publication(earlier)
+    repository.finish_publication(_finish(earlier, PublicationStatus.SUCCESS))
+    repository.save_memberships(
+        (
+            _membership_record(
+                "000001.SZ",
+                SectorType.INDUSTRY,
+                "BK0899.DC",
+                "旧行业",
+                trade_date=TARGET_DATE - timedelta(days=1),
+            ),
+        )
+    )
+    reader = ReadSectorRadar(repository)
+
+    membership = reader.stock_membership(
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="000001.SZ")
+    )
+
+    assert membership.trade_date == TARGET_DATE
+    assert membership.industries == (SectorRef(code="BK0902.DC", name="房地产"),)
+    behind = reader.stock_membership(
+        StockSectorQuery(trade_date=TARGET_DATE - timedelta(days=1), ts_code="000001.SZ")
+    )
+    assert behind.trade_date == TARGET_DATE - timedelta(days=1)
+    assert behind.industries == (SectorRef(code="BK0899.DC", name="旧行业"),)
+    assert behind.concepts == ()
+
+
+def test_stock_membership_without_any_publication_is_no_data() -> None:
+    reader = ReadSectorRadar(InMemorySectorRadarRepository())
+
+    membership = reader.stock_membership(
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="000001.SZ")
+    )
+
+    assert membership.status == "no_data"
+    assert membership.trade_date is None
+    assert membership.industries == ()
+    assert membership.concepts == ()
+    assert membership.concept_total == 0
+
+
+def test_stock_membership_query_rejects_invalid_values() -> None:
+    with pytest.raises(ValueError):
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="  ")
+    with pytest.raises(ValueError):
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="x" * 13)
+    with pytest.raises(ValueError):
+        StockSectorQuery(trade_date=TARGET_DATE, ts_code="000001.SZ", concept_limit=0)
diff --git a/zhixing-web/src/features/sector-radar/api/sector-radar.api.test.ts b/zhixing-web/src/features/sector-radar/api/sector-radar.api.test.ts
index a77a8be..f20223b 100644
--- a/zhixing-web/src/features/sector-radar/api/sector-radar.api.test.ts
+++ b/zhixing-web/src/features/sector-radar/api/sector-radar.api.test.ts
@@ -4,7 +4,11 @@ const requestJson = vi.hoisted(() => vi.fn())
 
 vi.mock("@/shared/api/request-json", () => ({ requestJson }))
 
-import { getSectorRadarDates, getSectorRadarRankings } from "./sector-radar.api"
+import {
+  getSectorRadarDates,
+  getSectorRadarRankings,
+  getStockSectorMembership,
+} from "./sector-radar.api"
 
 const publication = {
   publication_id: "publication-1",
@@ -180,3 +184,59 @@ describe("sector radar API adapters", () => {
     ).rejects.toThrow("rankings.rows[0].rank_percentile must be greater than 0")
   })
 })
+
+describe("stock sector membership adapter", () => {
+  const membershipPayload = {
+    status: "success",
+    ts_code: "000001.SZ",
+    requested_trade_date: "2026-08-28",
+    trade_date: "2026-08-28",
+    industries: [{ code: "BK0901.DC", name: "银行" }],
+    concepts: [
+      { code: "BK0001.DC", name: "机器人" },
+      { code: "BK0002.DC", name: "人工智能" },
+    ],
+    concept_total: 2,
+    concept_limit: 20,
+  }
+
+  it("requests the snake-case endpoint and validates the payload", async () => {
+    requestJson.mockResolvedValue(membershipPayload)
+
+    const result = await getStockSectorMembership("000001.SZ", "2026-08-28")
+
+    expect(requestJson).toHaveBeenCalledWith(
+      "/api/v1/sector-radar/stocks/000001.SZ/membership?trade_date=2026-08-28",
+      { signal: undefined },
+    )
+    expect(result).toEqual(membershipPayload)
+  })
+
+  it("keeps the no_data status with a null snapshot date", async () => {
+    requestJson.mockResolvedValue({
+      ...membershipPayload,
+      status: "no_data",
+      trade_date: null,
+      industries: [],
+      concepts: [],
+      concept_total: 0,
+    })
+
+    const result = await getStockSectorMembership("000001.SZ", "2026-08-28")
+
+    expect(result.status).toBe("no_data")
+    expect(result.trade_date).toBeNull()
+    expect(result.industries).toEqual([])
+  })
+
+  it("rejects a membership response with invalid sector references", async () => {
+    requestJson.mockResolvedValue({
+      ...membershipPayload,
+      industries: [{ code: "BK0901.DC", name: " " }],
+    })
+
+    await expect(
+      getStockSectorMembership("000001.SZ", "2026-08-28"),
+    ).rejects.toThrow("membership.industries[0].name must be a non-empty string")
+  })
+})
diff --git a/zhixing-web/src/features/sector-radar/api/sector-radar.api.ts b/zhixing-web/src/features/sector-radar/api/sector-radar.api.ts
index dd5e1ba..4dd0336 100644
--- a/zhixing-web/src/features/sector-radar/api/sector-radar.api.ts
+++ b/zhixing-web/src/features/sector-radar/api/sector-radar.api.ts
@@ -14,6 +14,8 @@ import {
   type RadarRankingRow,
   type RadarRankingsQuery,
   type RadarRankingsResponse,
+  type StockSectorMembershipResponse,
+  type StockSectorRef,
 } from "./sector-radar.types"
 
 type JsonRecord = Record<string, unknown>
@@ -145,6 +147,69 @@ export function parseRadarRankingsResponse(
   }
 }
 
+/**
+ * Fetch one stock's industries and concepts from the last-good build snapshot.
+ *
+ * @param tsCode - Stock code such as `000001.SZ`.
+ * @param tradeDate - Requested trade date; the backend answers with the
+ *   newest snapshot at or before it and reports that exact date.
+ * @param signal - React Query cancellation signal forwarded to fetch.
+ * @returns A validated membership response with grouped sector references.
+ * @throws Error when the server response violates the stable HTTP contract.
+ */
+export async function getStockSectorMembership(
+  tsCode: string,
+  tradeDate: string,
+  signal?: AbortSignal,
+) {
+  const params = new URLSearchParams({ trade_date: tradeDate })
+  const payload = await requestJson<unknown>(
+    `/api/v1/sector-radar/stocks/${encodeURIComponent(tsCode)}/membership?${params.toString()}`,
+    { signal },
+  )
+  return parseStockSectorMembershipResponse(payload)
+}
+
+/** Validate one stock-membership response at the feature boundary. */
+export function parseStockSectorMembershipResponse(
+  value: unknown,
+): StockSectorMembershipResponse {
+  const record = readRecord(value, "membership")
+  return {
+    status: readEnum(record.status, ["success", "no_data"], "membership.status"),
+    ts_code: readNonEmptyString(record.ts_code, "membership.ts_code"),
+    requested_trade_date: readDate(
+      record.requested_trade_date,
+      "membership.requested_trade_date",
+    ),
+    trade_date: readNullableDate(record.trade_date, "membership.trade_date"),
+    industries: readSectorRefs(record.industries, "membership.industries"),
+    concepts: readSectorRefs(record.concepts, "membership.concepts"),
+    concept_total: readIntegerInRange(
+      record.concept_total,
+      0,
+      Number.MAX_SAFE_INTEGER,
+      "membership.concept_total",
+    ),
+    concept_limit: readIntegerInRange(
+      record.concept_limit,
+      1,
+      100,
+      "membership.concept_limit",
+    ),
+  }
+}
+
+function readSectorRefs(value: unknown, path: string): StockSectorRef[] {
+  return readArray(value, path).map((item, index) => {
+    const ref = readRecord(item, `${path}[${index}]`)
+    return {
+      code: readNonEmptyString(ref.code, `${path}[${index}].code`),
+      name: readNonEmptyString(ref.name, `${path}[${index}].name`),
+    }
+  })
+}
+
 function readNullablePublication(
   value: unknown,
   path: string,
diff --git a/zhixing-web/src/features/sector-radar/api/sector-radar.query.ts b/zhixing-web/src/features/sector-radar/api/sector-radar.query.ts
index 50f8c6a..fc49abf 100644
--- a/zhixing-web/src/features/sector-radar/api/sector-radar.query.ts
+++ b/zhixing-web/src/features/sector-radar/api/sector-radar.query.ts
@@ -4,7 +4,7 @@ import {
   type InfiniteData,
 } from "@tanstack/react-query"
 
-import { getSectorRadarDates, getSectorRadarRankings } from "./sector-radar.api"
+import { getSectorRadarDates, getSectorRadarRankings, getStockSectorMembership } from "./sector-radar.api"
 import type {
   RadarRankingsQuery,
   RadarRankingsResponse,
@@ -12,6 +12,34 @@ import type {
 
 export const sectorRadarDatesQueryKey = ["sectorRadar", "dates"] as const
 
+export const stockSectorMembershipQueryKey = (
+  tsCode?: string,
+  tradeDate?: string,
+) =>
+  [
+    "sectorRadar",
+    "stockMembership",
+    tsCode ?? "none",
+    tradeDate ?? "none",
+  ] as const
+
+/**
+ * Read one stock's point-in-time industries and concepts for a detail view.
+ *
+ * Disabled until both the stock code and target trade date are known; the
+ * query stays cached per code-date pair so switching selections refetches
+ * only unseen pairs.
+ */
+export function useStockSectorMembership(tsCode?: string, tradeDate?: string) {
+  return useQuery({
+    enabled: Boolean(tsCode && tradeDate),
+    queryFn: ({ signal }) =>
+      getStockSectorMembership(tsCode ?? "", tradeDate ?? "", signal),
+    queryKey: stockSectorMembershipQueryKey(tsCode, tradeDate),
+    staleTime: 5 * 60 * 1000,
+  })
+}
+
 export const sectorRadarRankingsQueryKey = (query: RadarRankingsQuery) =>
   [
     "sectorRadar",
diff --git a/zhixing-web/src/features/sector-radar/api/sector-radar.types.ts b/zhixing-web/src/features/sector-radar/api/sector-radar.types.ts
index 1300fca..51253ac 100644
--- a/zhixing-web/src/features/sector-radar/api/sector-radar.types.ts
+++ b/zhixing-web/src/features/sector-radar/api/sector-radar.types.ts
@@ -111,3 +111,19 @@ export interface RadarRankingsQuery {
 export interface SectorRadarRouteSearch extends RadarRankingsQuery {
   search: string
 }
+
+export interface StockSectorRef {
+  code: string
+  name: string
+}
+
+export interface StockSectorMembershipResponse {
+  status: "success" | "no_data"
+  ts_code: string
+  requested_trade_date: string
+  trade_date: string | null
+  industries: StockSectorRef[]
+  concepts: StockSectorRef[]
+  concept_total: number
+  concept_limit: number
+}
diff --git a/zhixing-web/src/features/selection/components/signal-detail-panel.test.tsx b/zhixing-web/src/features/selection/components/signal-detail-panel.test.tsx
new file mode 100644
index 0000000..f7aeef5
--- /dev/null
+++ b/zhixing-web/src/features/selection/components/signal-detail-panel.test.tsx
@@ -0,0 +1,128 @@
+import { render, screen } from "@testing-library/react"
+import { beforeEach, describe, expect, it, vi } from "vitest"
+
+import type { SelectionStockResult } from "../api/selection.types"
+import { SignalDetailPanel } from "./signal-detail-panel"
+
+const useSelectionChart = vi.fn()
+const useStockSectorMembership = vi.fn()
+
+vi.mock("../api/selection.query", () => ({
+  useSelectionChart: (...args: unknown[]) => useSelectionChart(...args),
+}))
+
+vi.mock("@/features/sector-radar/api/sector-radar.query", () => ({
+  useStockSectorMembership: (...args: unknown[]) =>
+    useStockSectorMembership(...args),
+}))
+
+vi.mock("./selection-chart", () => ({
+  SelectionChart: () => <div>selection-chart</div>,
+}))
+
+vi.mock("./pattern-case-image", () => ({
+  PatternCaseImage: () => <div>pattern-case-image</div>,
+}))
+
+const stock: SelectionStockResult = {
+  close: 10.5,
+  name: "平安银行",
+  score: null,
+  signals: [],
+  strategy: "zhixing_b1",
+  target_trade_date: "2026-08-28",
+  ts_code: "000001.SZ",
+}
+
+describe("SignalDetailPanel", () => {
+  beforeEach(() => {
+    useSelectionChart.mockReturnValue({
+      data: undefined,
+      isError: false,
+      isPending: true,
+    })
+    useStockSectorMembership.mockReturnValue({
+      data: undefined,
+      isError: false,
+      isPending: true,
+    })
+  })
+
+  it("shows the stock industry and concept boards from the membership query", () => {
+    useStockSectorMembership.mockReturnValue({
+      data: {
+        status: "success",
+        ts_code: "000001.SZ",
+        requested_trade_date: "2026-08-28",
+        trade_date: "2026-08-28",
+        industries: [{ code: "BK0901.DC", name: "银行" }],
+        concepts: [
+          { code: "BK0001.DC", name: "机器人" },
+          { code: "BK0002.DC", name: "人工智能" },
+        ],
+        concept_total: 2,
+        concept_limit: 20,
+      },
+      isError: false,
+      isPending: false,
+    })
+
+    render(<SignalDetailPanel stock={stock} />)
+
+    expect(screen.getByText("行业：银行")).toBeInTheDocument()
+    expect(screen.getByText("板块")).toBeInTheDocument()
+    expect(screen.getByText("机器人")).toBeInTheDocument()
+    expect(screen.getByText("人工智能")).toBeInTheDocument()
+    expect(screen.queryByText(/等 \d+ 个/)).not.toBeInTheDocument()
+  })
+
+  it("caps visible concepts and reports the total", () => {
+    const concepts = Array.from({ length: 10 }, (_, index) => ({
+      code: `BK${String(index + 1).padStart(4, "0")}.DC`,
+      name: `板块${index + 1}`,
+    }))
+    useStockSectorMembership.mockReturnValue({
+      data: {
+        status: "success",
+        ts_code: "000001.SZ",
+        requested_trade_date: "2026-08-28",
+        trade_date: "2026-08-28",
+        industries: [],
+        concepts,
+        concept_total: 10,
+        concept_limit: 20,
+      },
+      isError: false,
+      isPending: false,
+    })
+
+    render(<SignalDetailPanel stock={stock} />)
+
+    expect(screen.getByText("板块1")).toBeInTheDocument()
+    expect(screen.getByText("板块8")).toBeInTheDocument()
+    expect(screen.queryByText("板块9")).not.toBeInTheDocument()
+    expect(screen.getByText("等 10 个")).toBeInTheDocument()
+  })
+
+  it("hides the sector rows when the membership query returns no data", () => {
+    useStockSectorMembership.mockReturnValue({
+      data: {
+        status: "no_data",
+        ts_code: "000001.SZ",
+        requested_trade_date: "2026-08-28",
+        trade_date: null,
+        industries: [],
+        concepts: [],
+        concept_total: 0,
+        concept_limit: 20,
+      },
+      isError: false,
+      isPending: false,
+    })
+
+    render(<SignalDetailPanel stock={stock} />)
+
+    expect(screen.queryByText(/行业：/)).not.toBeInTheDocument()
+    expect(screen.queryByText("板块")).not.toBeInTheDocument()
+  })
+})
diff --git a/zhixing-web/src/features/selection/components/signal-detail-panel.tsx b/zhixing-web/src/features/selection/components/signal-detail-panel.tsx
index e772dc8..ea4b1a0 100644
--- a/zhixing-web/src/features/selection/components/signal-detail-panel.tsx
+++ b/zhixing-web/src/features/selection/components/signal-detail-panel.tsx
@@ -1,5 +1,6 @@
 import { lazy, Suspense } from "react"
 import { Search } from "lucide-react"
+import { useStockSectorMembership } from "@/features/sector-radar/api/sector-radar.query"
 import { useSelectionChart } from "../api/selection.query"
 
 import { Card } from "@/shared/ui/card"
@@ -18,6 +19,8 @@ const SelectionChart = lazy(() =>
   })),
 )
 
+const displayedConceptCount = 8
+
 interface SignalDetailPanelProps {
   stock: SelectionStockResult | undefined
 }
@@ -28,6 +31,10 @@ export function SignalDetailPanel({ stock }: SignalDetailPanelProps) {
     stock?.target_trade_date,
     stock?.strategy,
   )
+  const membershipQuery = useStockSectorMembership(
+    stock?.ts_code,
+    stock?.target_trade_date,
+  )
 
   if (!stock) {
     return (
@@ -63,6 +70,19 @@ export function SignalDetailPanel({ stock }: SignalDetailPanelProps) {
     },
   ]
 
+  const membership =
+    membershipQuery.data?.status === "success" ? membershipQuery.data : undefined
+  const industries = membership?.industries ?? []
+  const concepts = membership?.concepts ?? []
+  const extraConceptCount = Math.max(
+    0,
+    concepts.length - displayedConceptCount,
+  )
+  const sectorSnapshotTitle =
+    membership?.trade_date != null
+      ? `板块成分截至 ${membership.trade_date}`
+      : undefined
+
   return (
     <aside
       aria-label="当前股票详情"
@@ -117,6 +137,33 @@ export function SignalDetailPanel({ stock }: SignalDetailPanelProps) {
             ¥ {stock.close.toFixed(2)}
           </p>
 
+          {industries.length > 0 && (
+            <p className="mt-1 text-xs text-muted-foreground">
+              行业：{industries.map((industry) => industry.name).join("、")}
+            </p>
+          )}
+          {concepts.length > 0 && (
+            <div
+              className="mt-2 flex flex-wrap items-center gap-1"
+              title={sectorSnapshotTitle}
+            >
+              <span className="text-xs text-muted-foreground">板块</span>
+              {concepts.slice(0, displayedConceptCount).map((concept) => (
+                <span
+                  className="rounded bg-muted px-1.5 py-0.5 text-xs"
+                  key={concept.code}
+                >
+                  {concept.name}
+                </span>
+              ))}
+              {extraConceptCount > 0 && (
+                <span className="text-xs text-muted-foreground">
+                  等 {concepts.length} 个
+                </span>
+              )}
+            </div>
+          )}
+
           <dl className="mt-3 divide-y divide-border/60 border-y border-border/60 text-xs">
             {metricRows.map((row) => (
               <div
diff --git a/zhixing-web/src/features/selection/pages/selection-results-page.test.tsx b/zhixing-web/src/features/selection/pages/selection-results-page.test.tsx
index 74350b5..0baf438 100644
--- a/zhixing-web/src/features/selection/pages/selection-results-page.test.tsx
+++ b/zhixing-web/src/features/selection/pages/selection-results-page.test.tsx
@@ -17,6 +17,7 @@ import { SelectionResultsPage } from "./selection-results-page"
 const routerNavigate = vi.hoisted(() => vi.fn())
 const useSelectionResults = vi.fn()
 const useSelectionChart = vi.fn()
+const useStockSectorMembership = vi.fn()
 const useSelectionRun = vi.fn()
 const useTriggerSelectionRun = vi.fn()
 const mutate = vi.fn()
@@ -36,6 +37,11 @@ vi.mock("@/features/selection/api/selection.query", async () => {
   }
 })
 
+vi.mock("@/features/sector-radar/api/sector-radar.query", () => ({
+  useStockSectorMembership: (...args: unknown[]) =>
+    useStockSectorMembership(...args),
+}))
+
 vi.mock("@tanstack/react-router", () => ({
   useNavigate: () => routerNavigate,
   useSearch: () => ({
@@ -157,6 +163,11 @@ describe("SelectionResultsPage", () => {
       isError: false,
       isPending: false,
     })
+    useStockSectorMembership.mockReturnValue({
+      data: undefined,
+      isError: false,
+      isPending: false,
+    })
     useSelectionResults.mockReturnValue(selectionQueryResult(selectedResult))
     useSelectionRun.mockReturnValue(emptySelectionQuery())
     useTriggerSelectionRun.mockReturnValue({