diff --git a/api/routers/account.py b/api/routers/account.py
new file mode 100644
index 0000000..cb1f628
--- /dev/null
+++ b/api/routers/account.py
@@ -0,0 +1,31 @@
+"""资金账户路由：余额查询、余额加减（业务在 service/account.py，路由只做编排）。"""
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from api.deps import get_current_user
+from config.deps import get_db
+from model.sys_user import SysUser
+from schemas.account import AdjustReq
+from service import account as account_service
+from utils.response import success
+
+router = APIRouter()
+
+
+@router.get("/account/balance", summary="查询当前用户余额")
+async def balance(
+    user: SysUser = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await account_service.get_balance(db, user)
+    return success(result.model_dump(mode="json"))
+
+
+@router.post("/account/adjust", summary="调整余额（add=充值 / sub=提现）")
+async def adjust(
+    req: AdjustReq,
+    user: SysUser = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await account_service.adjust_balance(db, user, req.direction, req.amount)
+    return success(result.model_dump(mode="json"))
diff --git a/api/routers/holdings.py b/api/routers/holdings.py
new file mode 100644
index 0000000..2ae4ac9
--- /dev/null
+++ b/api/routers/holdings.py
@@ -0,0 +1,20 @@
+"""持仓路由：查询当前用户持仓（业务在 service/holdings.py，路由只做编排）。"""
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from api.deps import get_current_user
+from config.deps import get_db
+from model.sys_user import SysUser
+from service import holdings as holdings_service
+from utils.response import success
+
+router = APIRouter()
+
+
+@router.get("/holdings", summary="查询当前用户持仓（持有中）")
+async def list_holdings(
+    user: SysUser = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await holdings_service.get_holdings(db, user)
+    return success([h.model_dump(mode="json") for h in result])
diff --git a/api/routers/purchase.py b/api/routers/purchase.py
new file mode 100644
index 0000000..944155b
--- /dev/null
+++ b/api/routers/purchase.py
@@ -0,0 +1,23 @@
+
+"""申购路由：申购基金产品（业务在 service/purchase.py，路由只做编排）。"""
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from api.deps import get_current_user
+from config.deps import get_db
+from model.sys_user import SysUser
+from schemas.purchase import PurchaseReq
+from service import purchase as purchase_service
+from utils.response import success
+
+router = APIRouter()
+
+
+@router.post("/purchase", summary="申购基金产品")
+async def purchase(
+    req: PurchaseReq,
+    user: SysUser = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await purchase_service.purchase(db, user, req.product_id, req.amount)
+    return success(result.model_dump(mode="json"))
diff --git a/api/routers/redeem.py b/api/routers/redeem.py
new file mode 100644
index 0000000..768ce79
--- /dev/null
+++ b/api/routers/redeem.py
@@ -0,0 +1,22 @@
+"""赎回路由：赎回基金产品（业务在 service/redeem.py，路由只做编排）。"""
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from api.deps import get_current_user
+from config.deps import get_db
+from model.sys_user import SysUser
+from schemas.redeem import RedeemReq
+from service import redeem as redeem_service
+from utils.response import success
+
+router = APIRouter()
+
+
+@router.post("/redeem", summary="赎回基金产品")
+async def redeem(
+    req: RedeemReq,
+    user: SysUser = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await redeem_service.redeem(db, user, req.product_id, req.shares)
+    return success(result.model_dump(mode="json"))
diff --git a/model/fin_account.py b/model/fin_account.py
new file mode 100644
index 0000000..207d923
--- /dev/null
+++ b/model/fin_account.py
@@ -0,0 +1,33 @@
+"""fin_account 客户资金账户表 ORM 模型（现金余额，一人一户）。
+
+balance 为账户总余额（含冻结部分），可用余额 = balance - frozen_amount，不落库。
+"""
+from __future__ import annotations
+
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import BigInteger, DateTime, Integer, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from model.base import Base
+
+
+class FinAccount(Base):
+    __tablename__ = "fin_account"
+    __table_args__ = {"comment": "客户资金账户表（现金余额，申购扣款/赎回入账的账务载体）"}
+
+    customer_id: Mapped[int] = mapped_column(
+        BigInteger, primary_key=True, autoincrement=False
+    )
+    balance: Mapped[Decimal] = mapped_column(Numeric(18, 2), server_default="0")
+    frozen_amount: Mapped[Decimal] = mapped_column(Numeric(18, 2), server_default="0")
+    currency: Mapped[str] = mapped_column(String(8), server_default="CNY")
+    status: Mapped[str] = mapped_column(String(16), server_default="正常")
+    version: Mapped[int] = mapped_column(Integer, server_default="0")
+    create_time: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now()
+    )
+    update_time: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
diff --git a/model/fin_holdings.py b/model/fin_holdings.py
new file mode 100644
index 0000000..b312c0e
--- /dev/null
+++ b/model/fin_holdings.py
@@ -0,0 +1,29 @@
+"""fin_holdings 持仓表 ORM 模型（当前/历史持仓快照）。"""
+from __future__ import annotations
+
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import BigInteger, DateTime, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from model.base import Base
+
+
+class FinHoldings(Base):
+    __tablename__ = "fin_holdings"
+    __table_args__ = {"comment": "持仓表（当前/历史持仓快照）"}
+
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
+    customer_id: Mapped[int] = mapped_column(BigInteger)
+    product_id: Mapped[int] = mapped_column(BigInteger)
+    shares: Mapped[Decimal] = mapped_column(Numeric(18, 4), server_default="0")
+    cost_amount: Mapped[Decimal] = mapped_column(Numeric(18, 2), server_default="0")
+    current_value: Mapped[Decimal] = mapped_column(Numeric(18, 2), server_default="0")
+    profit_loss: Mapped[Decimal] = mapped_column(Numeric(18, 2), server_default="0")
+    profit_ratio: Mapped[Decimal] = mapped_column(Numeric(8, 4), server_default="0")
+    status: Mapped[str] = mapped_column(String(16), server_default="持有中")
+    create_time: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    update_time: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
diff --git a/repositories/fin_account.py b/repositories/fin_account.py
new file mode 100644
index 0000000..831d943
--- /dev/null
+++ b/repositories/fin_account.py
@@ -0,0 +1,97 @@
+"""fin_account 仓储：按客户 ID 取资金账户 + 余额加减（原子 UPDATE）。
+
+注：本表主键为 customer_id（非 id），故不复用 BaseRepository.delete/count 中的 id 约定。
+余额增减用原子 UPDATE（balance = balance ± delta）防并发丢更新，不依赖乐观锁重试。
+"""
+from __future__ import annotations
+
+from decimal import Decimal
+
+from sqlalchemy import select, update
+
+from model.fin_account import FinAccount
+from repositories.base import BaseRepository
+
+
+class FinAccountRepo(BaseRepository):
+    model = FinAccount
+
+    async def get_by_customer_id(self, customer_id: int) -> FinAccount | None:
+        return await self.db.scalar(
+            select(FinAccount).where(FinAccount.customer_id == customer_id)
+        )
+
+    async def create(self, customer_id: int, balance: Decimal) -> FinAccount:
+        """开资金户（充值时账户不存在则自动开户入账）。"""
+        account = FinAccount(customer_id=customer_id, balance=balance)
+        self.db.add(account)
+        await self.db.commit()
+        await self.db.refresh(account)
+        return account
+
+    async def add_balance(self, customer_id: int, delta: Decimal) -> FinAccount:
+        """入账：balance += delta，原子自增后回读最新余额。"""
+        await self.db.execute(
+            update(FinAccount)
+            .where(FinAccount.customer_id == customer_id)
+            .values(
+                balance=FinAccount.balance + delta,
+                version=FinAccount.version + 1,
+            )
+        )
+        await self.db.commit()
+        return await self.get_by_customer_id(customer_id)
+
+    async def subtract_balance(
+        self, customer_id: int, delta: Decimal
+    ) -> FinAccount | None:
+        """出账：balance -= delta，可用余额（balance - frozen_amount）不足时返回 None。"""
+        result = await self.db.execute(
+            update(FinAccount)
+            .where(
+                FinAccount.customer_id == customer_id,
+                FinAccount.balance - FinAccount.frozen_amount >= delta,
+            )
+            .values(
+                balance=FinAccount.balance - delta,
+                version=FinAccount.version + 1,
+            )
+        )
+        await self.db.commit()
+        if result.rowcount == 0:
+            return None
+        return await self.get_by_customer_id(customer_id)
+
+    async def deduct_balance(self, customer_id: int, delta: Decimal) -> bool:
+        """申购事务内扣款：balance -= delta（可用余额不足则不动）。
+
+        不 commit，由 service 层事务统一提交，保证「扣款 + 加仓」原子性。
+        可用余额（balance - frozen_amount）不足时返回 False。
+        """
+        result = await self.db.execute(
+            update(FinAccount)
+            .where(
+                FinAccount.customer_id == customer_id,
+                FinAccount.balance - FinAccount.frozen_amount >= delta,
+            )
+            .values(
+                balance=FinAccount.balance - delta,
+                version=FinAccount.version + 1,
+            )
+        )
+        return result.rowcount > 0
+
+    async def credit_balance(self, customer_id: int, delta: Decimal) -> bool:
+        """赎回事务内入账：balance += delta。
+
+        不 commit，由 service 层事务统一提交，保证「减仓 + 入账」原子性。
+        """
+        result = await self.db.execute(
+            update(FinAccount)
+            .where(FinAccount.customer_id == customer_id)
+            .values(
+                balance=FinAccount.balance + delta,
+                version=FinAccount.version + 1,
+            )
+        )
+        return result.rowcount > 0
diff --git a/repositories/fin_customer_profile.py b/repositories/fin_customer_profile.py
new file mode 100644
index 0000000..d168254
--- /dev/null
+++ b/repositories/fin_customer_profile.py
@@ -0,0 +1,21 @@
+"""fin_customer_profile 画像仓储：按客户 ID 取画像。
+
+注：本表主键为 customer_id（非 id），故不复用 BaseRepository.get 的 id 约定。
+"""
+from __future__ import annotations
+
+from sqlalchemy import select
+
+from model.fin_customer_profile import FinCustomerProfile
+from repositories.base import BaseRepository
+
+
+class FinCustomerProfileRepo(BaseRepository):
+    model = FinCustomerProfile
+
+    async def get_by_customer_id(self, customer_id: int) -> FinCustomerProfile | None:
+        return await self.db.scalar(
+            select(FinCustomerProfile).where(
+                FinCustomerProfile.customer_id == customer_id
+            )
+        )
diff --git a/repositories/fin_holdings.py b/repositories/fin_holdings.py
new file mode 100644
index 0000000..253a2a9
--- /dev/null
+++ b/repositories/fin_holdings.py
@@ -0,0 +1,75 @@
+"""fin_holdings 持仓仓储：按客户（+状态）查持仓、申购加仓 upsert、赎回减仓。"""
+from __future__ import annotations
+
+from decimal import Decimal
+
+from sqlalchemy import case, select, update
+from sqlalchemy.dialects.mysql import insert as mysql_insert
+
+from model.fin_holdings import FinHoldings
+from repositories.base import BaseRepository
+
+
+class FinHoldingsRepo(BaseRepository):
+    model = FinHoldings
+
+    async def list_by_customer(
+        self, customer_id: int, status: str | None = None
+    ) -> list[FinHoldings]:
+        """按客户 ID 查持仓，可按状态过滤（status=None 表示不过滤）。"""
+        stmt = select(FinHoldings).where(FinHoldings.customer_id == customer_id)
+        if status is not None:
+            stmt = stmt.where(FinHoldings.status == status)
+        stmt = stmt.order_by(FinHoldings.id)
+        return list((await self.db.scalars(stmt)).all())
+
+    async def get_by_customer_product(
+        self, customer_id: int, product_id: int
+    ) -> FinHoldings | None:
+        return await self.db.scalar(
+            select(FinHoldings).where(
+                FinHoldings.customer_id == customer_id,
+                FinHoldings.product_id == product_id,
+            )
+        )
+
+    async def upsert(
+        self, customer_id: int, product_id: int, add_shares: Decimal, add_cost: Decimal
+    ) -> None:
+        """申购加仓：有则加份额/成本，无则新增（靠 uk_customer_product 唯一键）。不 commit。"""
+        stmt = mysql_insert(FinHoldings).values(
+            customer_id=customer_id,
+            product_id=product_id,
+            shares=add_shares,
+            cost_amount=add_cost,
+        )
+        stmt = stmt.on_duplicate_key_update(
+            shares=FinHoldings.shares + add_shares,
+            cost_amount=FinHoldings.cost_amount + add_cost,
+        )
+        await self.db.execute(stmt)
+
+    async def redeem(
+        self, customer_id: int, product_id: int, redeem_shares: Decimal
+    ) -> bool:
+        """赎回减仓：shares -= redeem_shares，份额归 0 时状态置'已清仓'。
+
+        持仓份额不足（含无持仓、shares=0）时不动作，返回 False。
+        不 commit，由 service 层事务统一提交，保证「减仓 + 入账」原子性。
+        """
+        result = await self.db.execute(
+            update(FinHoldings)
+            .where(
+                FinHoldings.customer_id == customer_id,
+                FinHoldings.product_id == product_id,
+                FinHoldings.shares >= redeem_shares,
+            )
+            .values(
+                shares=FinHoldings.shares - redeem_shares,
+                status=case(
+                    (FinHoldings.shares - redeem_shares == 0, "已清仓"),
+                    else_=FinHoldings.status,
+                ),
+            )
+        )
+        return result.rowcount > 0
diff --git a/repositories/fin_product.py b/repositories/fin_product.py
new file mode 100644
index 0000000..1b17e52
--- /dev/null
+++ b/repositories/fin_product.py
@@ -0,0 +1,7 @@
+"""fin_product 产品仓储：申购按主键取产品（复用 BaseRepository.get）。"""
+from model.fin_product import FinProduct
+from repositories.base import BaseRepository
+
+
+class FinProductRepo(BaseRepository):
+    model = FinProduct
diff --git a/schemas/account.py b/schemas/account.py
new file mode 100644
index 0000000..cfaa2b1
--- /dev/null
+++ b/schemas/account.py
@@ -0,0 +1,34 @@
+"""资金账户相关 DTO。
+
+金额统一序列化为两位小数字符串（如 "48000.00"），避免 JSON number 的浮点精度隐患。
+"""
+from datetime import datetime
+from decimal import Decimal
+from typing import Literal
+
+from pydantic import BaseModel, Field, field_serializer
+
+
+class BalanceResp(BaseModel):
+    """用户余额响应体。available_balance = balance - frozen_amount，由 service 派生。"""
+
+    customer_id: int
+    balance: Decimal
+    available_balance: Decimal
+    frozen_amount: Decimal
+    currency: str
+    status: str
+    update_time: datetime | None = None
+
+    @field_serializer("balance", "available_balance", "frozen_amount")
+    def _fmt_money(self, value: Decimal) -> str:
+        return f"{value:.2f}"
+
+
+class AdjustReq(BaseModel):
+    """加减余额入参。amount 为正数（元），direction 决定加/减。"""
+
+    direction: Literal["add", "sub"] = Field(
+        ..., description="add=入账(充值)，sub=出账(提现)"
+    )
+    amount: Decimal = Field(gt=0)
diff --git a/schemas/holdings.py b/schemas/holdings.py
new file mode 100644
index 0000000..437dd70
--- /dev/null
+++ b/schemas/holdings.py
@@ -0,0 +1,30 @@
+"""持仓相关 DTO。
+
+金额字段序列化为字符串，避免 JSON number 浮点精度隐患；
+份额 / 盈亏比例保留 4 位，金额保留 2 位。
+"""
+from decimal import Decimal
+
+from pydantic import BaseModel, field_serializer
+
+
+class HoldingResp(BaseModel):
+    """单条持仓记录。"""
+
+    id: int
+    customer_id: int
+    product_id: int
+    shares: Decimal
+    cost_amount: Decimal
+    current_value: Decimal
+    profit_loss: Decimal
+    profit_ratio: Decimal
+    status: str
+
+    @field_serializer("shares", "profit_ratio")
+    def _fmt_ratio(self, value: Decimal) -> str:
+        return f"{value:.4f}"
+
+    @field_serializer("cost_amount", "current_value", "profit_loss")
+    def _fmt_money(self, value: Decimal) -> str:
+        return f"{value:.2f}"
diff --git a/schemas/purchase.py b/schemas/purchase.py
new file mode 100644
index 0000000..2cd5680
--- /dev/null
+++ b/schemas/purchase.py
@@ -0,0 +1,24 @@
+"""申购相关 DTO。"""
+from decimal import Decimal
+
+from pydantic import BaseModel, Field, field_serializer
+
+from schemas.holdings import HoldingResp
+
+
+class PurchaseReq(BaseModel):
+    """申购入参。amount 为正数（元），按净值折算份额。"""
+
+    product_id: int
+    amount: Decimal = Field(gt=0)
+
+
+class PurchaseResp(BaseModel):
+    """申购结果：最新余额 + 该产品最新持仓。"""
+
+    balance: Decimal
+    holding: HoldingResp
+
+    @field_serializer("balance")
+    def _fmt_balance(self, value: Decimal) -> str:
+        return f"{value:.2f}"
diff --git a/schemas/redeem.py b/schemas/redeem.py
new file mode 100644
index 0000000..b80071c
--- /dev/null
+++ b/schemas/redeem.py
@@ -0,0 +1,24 @@
+"""赎回相关 DTO。"""
+from decimal import Decimal
+
+from pydantic import BaseModel, Field, field_serializer
+
+from schemas.holdings import HoldingResp
+
+
+class RedeemReq(BaseModel):
+    """赎回入参。shares 为正数（份额），按净值折算入账金额。"""
+
+    product_id: int
+    shares: Decimal = Field(gt=0)
+
+
+class RedeemResp(BaseModel):
+    """赎回结果：最新余额 + 该产品最新持仓。"""
+
+    balance: Decimal
+    holding: HoldingResp
+
+    @field_serializer("balance")
+    def _fmt_balance(self, value: Decimal) -> str:
+        return f"{value:.2f}"
diff --git a/service/account.py b/service/account.py
new file mode 100644
index 0000000..60d0469
--- /dev/null
+++ b/service/account.py
@@ -0,0 +1,80 @@
+"""资金账户服务：余额查询 + 余额加减（路由层只编排，不碰数据/逻辑）。"""
+from __future__ import annotations
+
+from decimal import Decimal
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from model.fin_account import FinAccount
+from model.sys_user import SysUser
+from repositories.fin_account import FinAccountRepo
+from schemas.account import BalanceResp
+from utils.exceptions import ForbiddenError, NotFoundError, ParamError
+
+_ZERO = Decimal("0.00")
+_DEFAULT_CURRENCY = "CNY"
+
+
+def _build_balance_resp(account: FinAccount) -> BalanceResp:
+    return BalanceResp(
+        customer_id=account.customer_id,
+        balance=account.balance,
+        available_balance=account.balance - account.frozen_amount,
+        frozen_amount=account.frozen_amount,
+        currency=account.currency,
+        status=account.status,
+        update_time=account.update_time,
+    )
+
+
+async def get_balance(db: AsyncSession, user: SysUser) -> BalanceResp:
+    """查询当前用户现金余额。
+
+    - 仅客户账号可查（员工共用 sys_user，但无资金账户）；
+    - 未开资金户时按零余额返回，不报错。
+    """
+    if user.user_type != "CUSTOMER":
+        raise ForbiddenError("仅客户账号可查询资金余额")
+
+    account = await FinAccountRepo(db).get_by_customer_id(user.id)
+    if account is None:
+        return BalanceResp(
+            customer_id=user.id,
+            balance=_ZERO,
+            available_balance=_ZERO,
+            frozen_amount=_ZERO,
+            currency=_DEFAULT_CURRENCY,
+            status="正常",
+        )
+
+    return _build_balance_resp(account)
+
+
+async def adjust_balance(
+    db: AsyncSession, user: SysUser, direction: str, amount: Decimal
+) -> BalanceResp:
+    """加减余额：direction=add 入账 / sub 出账。
+
+    - add：balance += amount，未开资金户时自动开户入账；
+    - sub：balance -= amount，可用余额（balance - frozen_amount）不足时报错。
+    """
+    if user.user_type != "CUSTOMER":
+        raise ForbiddenError("仅客户账号可调整余额")
+
+    repo = FinAccountRepo(db)
+    account = await repo.get_by_customer_id(user.id)
+
+    if direction == "add":
+        if account is None:
+            account = await repo.create(user.id, amount)
+        else:
+            account = await repo.add_balance(user.id, amount)
+    else:  # sub
+        if account is None:
+            raise NotFoundError("资金账户不存在")
+        updated = await repo.subtract_balance(user.id, amount)
+        if updated is None:
+            raise ParamError("可用余额不足")
+        account = updated
+
+    return _build_balance_resp(account)
diff --git a/service/holdings.py b/service/holdings.py
new file mode 100644
index 0000000..8b16926
--- /dev/null
+++ b/service/holdings.py
@@ -0,0 +1,37 @@
+"""持仓服务：查询当前客户持仓（路由层只编排，不碰数据/逻辑）。"""
+from __future__ import annotations
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from model.sys_user import SysUser
+from repositories.fin_holdings import FinHoldingsRepo
+from schemas.holdings import HoldingResp
+from utils.exceptions import ForbiddenError
+
+_HOLDING_STATUS = "持有中"
+
+
+async def get_holdings(db: AsyncSession, user: SysUser) -> list[HoldingResp]:
+    """查询当前客户的在持持仓（status=持有中）。
+
+    - 仅客户账号可查（员工共用 sys_user，但无持仓）；
+    - 无持仓返回空列表，不报错。
+    """
+    if user.user_type != "CUSTOMER":
+        raise ForbiddenError("仅客户账号可查询持仓")
+
+    holdings = await FinHoldingsRepo(db).list_by_customer(user.id, _HOLDING_STATUS)
+    return [
+        HoldingResp(
+            id=h.id,
+            customer_id=h.customer_id,
+            product_id=h.product_id,
+            shares=h.shares,
+            cost_amount=h.cost_amount,
+            current_value=h.current_value,
+            profit_loss=h.profit_loss,
+            profit_ratio=h.profit_ratio,
+            status=h.status,
+        )
+        for h in holdings
+    ]
diff --git a/service/purchase.py b/service/purchase.py
new file mode 100644
index 0000000..fa44f49
--- /dev/null
+++ b/service/purchase.py
@@ -0,0 +1,99 @@
+"""申购服务：风险匹配校验 + 余额扣减 + 持仓加仓（单事务原子）。"""
+from __future__ import annotations
+
+from decimal import ROUND_HALF_UP, Decimal
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from model.sys_user import SysUser
+from repositories.fin_account import FinAccountRepo
+from repositories.fin_customer_profile import FinCustomerProfileRepo
+from repositories.fin_holdings import FinHoldingsRepo
+from repositories.fin_product import FinProductRepo
+from schemas.holdings import HoldingResp
+from schemas.purchase import PurchaseResp
+from utils.exceptions import (
+    ForbiddenError,
+    NotFoundError,
+    NotSuitableError,
+    ParamError,
+)
+
+_MONEY = Decimal("0.01")
+_SHARES = Decimal("0.0001")
+
+# 风险等级 → 序号。兼容两套口径：R1~R5 与 保守~激进（同一映射）。
+_RISK_RANK = {
+    "R1": 1, "R2": 2, "R3": 3, "R4": 4, "R5": 5,
+    "保守": 1, "稳健": 2, "平衡": 3, "进取": 4, "激进": 5,
+}
+
+
+def _risk_rank(level: str | None) -> int | None:
+    """客户画像 / 产品的风险等级统一转序号；未知返回 None。"""
+    if not level:
+        return None
+    return _RISK_RANK.get(level.strip())
+
+
+async def purchase(
+    db: AsyncSession, user: SysUser, product_id: int, amount: Decimal
+) -> PurchaseResp:
+    """申购基金：校验通过后扣减余额并加仓，全程单事务。
+
+    - 仅客户可申购；
+    - 产品须在售且净值非空；
+    - 客户风险等级序号 >= 产品风险等级序号，否则 1005 拦截；
+    - 余额不足拦截；扣款 + 加仓要么都成、要么都回滚。
+    """
+    if user.user_type != "CUSTOMER":
+        raise ForbiddenError("仅客户账号可申购")
+
+    amount = amount.quantize(_MONEY, rounding=ROUND_HALF_UP)
+
+    product = await FinProductRepo(db).get(product_id)
+    if product is None:
+        raise NotFoundError("产品不存在")
+    if product.status != "在售":
+        raise ParamError("产品不在售")
+    if product.nav is None:
+        raise ParamError("产品暂无净值，无法申购")
+
+    profile = await FinCustomerProfileRepo(db).get_by_customer_id(user.id)
+    customer_rank = _risk_rank(profile.risk_level if profile else None)
+    if customer_rank is None:
+        raise NotSuitableError("客户无风险等级，无法申购")
+    product_rank = _risk_rank(product.risk_level)
+    if product_rank is None or customer_rank < product_rank:
+        raise NotSuitableError()
+
+    shares = (amount / product.nav).quantize(_SHARES, rounding=ROUND_HALF_UP)
+
+    account_repo = FinAccountRepo(db)
+    holdings_repo = FinHoldingsRepo(db)
+
+    try:
+        if not await account_repo.deduct_balance(user.id, amount):
+            raise ParamError("可用余额不足")
+        await holdings_repo.upsert(user.id, product_id, shares, amount)
+        await db.commit()
+    except Exception:
+        await db.rollback()
+        raise
+
+    account = await account_repo.get_by_customer_id(user.id)
+    holding = await holdings_repo.get_by_customer_product(user.id, product_id)
+    return PurchaseResp(
+        balance=account.balance,
+        holding=HoldingResp(
+            id=holding.id,
+            customer_id=holding.customer_id,
+            product_id=holding.product_id,
+            shares=holding.shares,
+            cost_amount=holding.cost_amount,
+            current_value=holding.current_value,
+            profit_loss=holding.profit_loss,
+            profit_ratio=holding.profit_ratio,
+            status=holding.status,
+        ),
+    )
diff --git a/service/redeem.py b/service/redeem.py
new file mode 100644
index 0000000..97af761
--- /dev/null
+++ b/service/redeem.py
@@ -0,0 +1,80 @@
+"""赎回服务：校验持仓 → 减仓 + 余额入账（单事务原子）。"""
+from __future__ import annotations
+
+from decimal import ROUND_HALF_UP, Decimal
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from model.sys_user import SysUser
+from repositories.fin_account import FinAccountRepo
+from repositories.fin_holdings import FinHoldingsRepo
+from repositories.fin_product import FinProductRepo
+from schemas.holdings import HoldingResp
+from schemas.redeem import RedeemResp
+from utils.exceptions import ForbiddenError, NotFoundError, ParamError
+
+_MONEY = Decimal("0.01")
+_SHARES = Decimal("0.0001")
+
+
+async def redeem(
+    db: AsyncSession, user: SysUser, product_id: int, shares: Decimal
+) -> RedeemResp:
+    """赎回基金：校验通过后减仓并按净值入账，全程单事务。
+
+    - 仅客户可赎回；
+    - 产品须存在且净值非空；
+    - 持仓须存在且份额 > 0，赎回份额不得超过持仓份额；
+    - 减仓（归 0 时置'已清仓'）+ 入账要么都成、要么都回滚。
+    """
+    if user.user_type != "CUSTOMER":
+        raise ForbiddenError("仅客户账号可赎回")
+
+    shares = shares.quantize(_SHARES, rounding=ROUND_HALF_UP)
+    if shares <= 0:
+        raise ParamError("赎回份额须大于 0")
+
+    product = await FinProductRepo(db).get(product_id)
+    if product is None:
+        raise NotFoundError("产品不存在")
+    if product.nav is None:
+        raise ParamError("产品暂无净值，无法赎回")
+
+    account_repo = FinAccountRepo(db)
+    holdings_repo = FinHoldingsRepo(db)
+
+    holding = await holdings_repo.get_by_customer_product(user.id, product_id)
+    if holding is None or holding.shares <= 0:
+        raise ParamError("无可赎回份额")
+    if holding.shares < shares:
+        raise ParamError("可赎回份额不足")
+
+    credited = (shares * product.nav).quantize(_MONEY, rounding=ROUND_HALF_UP)
+    if credited <= 0:
+        raise ParamError("赎回金额过低")
+
+    try:
+        if not await holdings_repo.redeem(user.id, product_id, shares):
+            raise ParamError("可赎回份额不足")
+        await account_repo.credit_balance(user.id, credited)
+        await db.commit()
+    except Exception:
+        await db.rollback()
+        raise
+
+    account = await account_repo.get_by_customer_id(user.id)
+    holding = await holdings_repo.get_by_customer_product(user.id, product_id)
+    return RedeemResp(
+        balance=account.balance,
+        holding=HoldingResp(
+            id=holding.id,
+            customer_id=holding.customer_id,
+            product_id=holding.product_id,
+            shares=holding.shares,
+            cost_amount=holding.cost_amount,
+            current_value=holding.current_value,
+            profit_loss=holding.profit_loss,
+            profit_ratio=holding.profit_ratio,
+            status=holding.status,
+        ),
+    )