diff --git a/backend/app/api/endpoints/portfolio.py b/backend/app/api/endpoints/portfolio.py
index 9c69eff..9166f48 100644
--- a/backend/app/api/endpoints/portfolio.py
+++ b/backend/app/api/endpoints/portfolio.py
@@ -603,6 +603,13 @@ async def sync_portfolio(db: AsyncSession = Depends(get_db), force: bool = True)
                     _realtime_price_map = {}
                 # ──────────────────────────────────────────────────────────────────
 
+                # 데이트레이딩 엔진이 보유 중인 종목 → strategy_type='daytrading' 태깅용
+                try:
+                    from app.services.daytrading.position_manager import day_trading_state as _dts
+                    _dt_codes = set(_dts.positions.keys())
+                except Exception:
+                    _dt_codes = set()
+
                 for item in balance_data["output1"]:
                     stock_code = item.get("pdno")
 
@@ -739,6 +746,8 @@ async def sync_portfolio(db: AsyncSession = Depends(get_db), force: bool = True)
                         h.profit_loss = profit_loss
                         h.profit_loss_rate = profit_loss_rate
                         h.market = exchange_code
+                        if stock_code in _dt_codes:
+                            h.strategy_type = "daytrading"
                         new_holdings.append(h)
                     else:
                         new_holding = Portfolio(
@@ -750,6 +759,7 @@ async def sync_portfolio(db: AsyncSession = Depends(get_db), force: bool = True)
                             profit_loss=profit_loss,
                             profit_loss_rate=profit_loss_rate,
                             market=exchange_code,
+                            strategy_type="daytrading" if stock_code in _dt_codes else "swing",
                         )
                         db.add(new_holding)
                         new_holdings.append(new_holding)
diff --git a/backend/app/services/daytrading/entry_service.py b/backend/app/services/daytrading/entry_service.py
index 3ad4ee6..478c21b 100644
--- a/backend/app/services/daytrading/entry_service.py
+++ b/backend/app/services/daytrading/entry_service.py
@@ -498,6 +498,9 @@ async def _try_enter(
             "entry_reason": signal.reason,
             "strategy_type": "daytrading",
         })
+        # 포트폴리오 화면 즉시 반영 (strategy_type='daytrading' 태깅 → 스윙 청산 로직 대상에서 제외)
+        from app.services.portfolio_cache_bridge import reflect_buy
+        await reflect_buy(stock_code, stock_name, quantity, current_price, strategy_type="daytrading")
         await enqueue_active_trade_upsert({
             "stock_code": stock_code,
             "stock_name": stock_name,
diff --git a/backend/app/services/daytrading/exit_service.py b/backend/app/services/daytrading/exit_service.py
index a9c262b..507f14e 100644
--- a/backend/app/services/daytrading/exit_service.py
+++ b/backend/app/services/daytrading/exit_service.py
@@ -275,6 +275,9 @@ async def _execute_exit(
     })
     if is_full_exit:
         await enqueue_close_active_trade(stock_code, strategy_name="day_trade")
+    # 포트폴리오 화면에서 즉시 제거/차감
+    from app.services.portfolio_cache_bridge import reflect_sell
+    await reflect_sell(stock_code, quantity, price, remaining_qty=max(0, int(total_qty) - int(quantity)))
 
     sell_label = f"{int(sell_pct * 100)}%" if sell_pct < 1.0 else "전량"
     logger.info(
diff --git a/backend/app/services/portfolio_cache_bridge.py b/backend/app/services/portfolio_cache_bridge.py
new file mode 100644
index 0000000..a8f3189
--- /dev/null
+++ b/backend/app/services/portfolio_cache_bridge.py
@@ -0,0 +1,111 @@
+"""portfolio_cache_bridge — 매매 엔진(데이트레이딩/스윙)에서 포트폴리오 화면 상태를 즉시 갱신.
+
+역할:
+  - 매수 직후: Portfolio 행 upsert(db_worker 큐) + 인메모리 캐시에 즉시 추가 (strategy_type 태깅)
+  - 매도 직후: Portfolio 수량 차감/0 (db_worker 큐) + 캐시에서 즉시 제거/차감 + 최근매도 기록
+    (KIS 잔고 반영 지연으로 동기화가 되살리는 것 방지)
+
+DB 쓰기는 전부 db_worker 큐 경유(CLAUDE.md §3.2). 캐시는 인메모리라 실시간 계층에서 호출 가능.
+portfolio.py 는 지연 import (순환 import·기동 순서 회피).
+"""
+import logging
+from decimal import Decimal
+
+logger = logging.getLogger(__name__)
+
+
+def _cache():
+    from app.api.endpoints.portfolio import portfolio_cache
+    return portfolio_cache
+
+
+async def reflect_buy(
+    stock_code: str,
+    stock_name: str,
+    quantity: int,
+    price: float,
+    strategy_type: str = "swing",
+    market: str = "KRX",
+) -> None:
+    """매수 체결 즉시 Portfolio(큐) + 캐시 반영."""
+    try:
+        from app.services.db_worker import enqueue_portfolio_upsert
+        from app.models.models import Portfolio
+
+        cache = _cache()
+        existing = next((h for h in cache.holdings if h.stock_code == stock_code), None)
+        if existing is not None:
+            old_qty = int(existing.quantity or 0)
+            old_avg = float(existing.average_price or price)
+            new_qty = old_qty + quantity
+            new_avg = (old_avg * old_qty + price * quantity) / new_qty if new_qty > 0 else price
+            existing.quantity = new_qty
+            existing.average_price = Decimal(str(round(new_avg, 2)))
+            existing.current_price = Decimal(str(price))
+            if strategy_type == "daytrading":
+                existing.strategy_type = "daytrading"
+            avg_for_db, qty_for_db = new_avg, new_qty
+        else:
+            cache.holdings.append(Portfolio(
+                stock_code=stock_code, stock_name=stock_name, quantity=quantity,
+                average_price=Decimal(str(price)), current_price=Decimal(str(price)),
+                profit_loss=Decimal("0"), profit_loss_rate=Decimal("0"),
+                market=market, strategy_type=strategy_type,
+                currency_code="KRW" if market == "KRX" else "USD",
+            ))
+            avg_for_db, qty_for_db = price, quantity
+
+        await enqueue_portfolio_upsert({
+            "stock_code": stock_code,
+            "stock_name": stock_name,
+            "quantity": qty_for_db,
+            "average_price": round(avg_for_db, 2),
+            "current_price": price,
+            "market": market,
+            "strategy_type": strategy_type,
+        })
+        await cache.apply_buy(stock_code, stock_name, quantity, price)
+    except Exception as e:
+        logger.warning(f"[cache_bridge] reflect_buy 실패 ({stock_code}): {e}")
+
+
+async def reflect_sell(
+    stock_code: str,
+    quantity: int,
+    price: float,
+    remaining_qty: int | None = None,
+) -> None:
+    """매도 체결 즉시 Portfolio(큐) 차감 + 캐시 제거/차감 + 최근매도 기록.
+
+    remaining_qty: 호출측이 아는 매도 후 잔량(권장). None이면 캐시 보유량 기준으로 계산
+    (캐시에 없으면 전량 매도로 간주하지 않고 DB 갱신을 건너뜀).
+    """
+    try:
+        from app.services.db_worker import enqueue_portfolio_upsert
+
+        cache = _cache()
+        existing = next((h for h in cache.holdings if h.stock_code == stock_code), None)
+        avg = float(existing.average_price or price) if existing is not None else price
+        if remaining_qty is not None:
+            remaining = max(0, int(remaining_qty))
+        elif existing is not None:
+            remaining = max(0, int(existing.quantity or 0) - quantity)
+        else:
+            remaining = None  # 알 수 없음 → DB 수량은 건드리지 않음
+        if existing is not None and remaining is not None:
+            if remaining <= 0:
+                cache.holdings = [h for h in cache.holdings if h.stock_code != stock_code]
+            else:
+                existing.quantity = remaining
+                existing.current_price = Decimal(str(price))
+
+        if remaining is not None:
+            await enqueue_portfolio_upsert({
+                "stock_code": stock_code,
+                "quantity": remaining,   # 0 → 목록에서 제외, 다음 동기화에서 삭제
+                "current_price": price,
+            })
+        cache.note_sell(stock_code, quantity)
+        await cache.apply_sell(stock_code, quantity, price, avg)
+    except Exception as e:
+        logger.warning(f"[cache_bridge] reflect_sell 실패 ({stock_code}): {e}")
diff --git a/backend/app/services/swing/exit_service.py b/backend/app/services/swing/exit_service.py
index 2ee49d8..3a69a4f 100644
--- a/backend/app/services/swing/exit_service.py
+++ b/backend/app/services/swing/exit_service.py
@@ -335,15 +335,17 @@ async def check_and_execute_exit_v2(db: AsyncSession) -> list[dict]:
                     "strategy_type": "swing",
                 })
 
+                # 포트폴리오 화면 즉시 반영 (Portfolio 수량 차감 + 캐시)
+                from app.services.portfolio_cache_bridge import reflect_sell
+                await reflect_sell(stock_code, sell_qty, latest_price, remaining_qty=quantity - sell_qty)
+
                 # 전량 청산이면 ActiveTrade 종료, 분할 매도면 remaining_pct 갱신
                 if sell_qty >= quantity:
                     await enqueue_close_active_trade(stock_code, strategy_name=None)
                 else:
                     # 분할 매도 후 remaining_pct 갱신 (반복 트리거 방지)
                     new_remaining = max(0.0, remaining_pct - sell_pct)
-                    from app.services.db_worker import (
-                        enqueue_active_trade_upsert, enqueue_portfolio_upsert,
-                    )
+                    from app.services.db_worker import enqueue_active_trade_upsert
                     _at_data = {
                         "stock_code": stock_code,
                         "remaining_pct": new_remaining,
@@ -364,13 +366,6 @@ async def check_and_execute_exit_v2(db: AsyncSession) -> list[dict]:
                             "entry_reason": "동기화 유입 포지션 (부분매도 시 자동 생성)",
                         })
                     await enqueue_active_trade_upsert(_at_data)
-                    # [FIX] 잔여 수량도 즉시 반영 — 다음 사이클이 동기화 전 원래 수량
-                    # 기준으로 매도 수량을 계산하지 않도록 (18주→9주 재매도 방지)
-                    await enqueue_portfolio_upsert({
-                        "stock_code": stock_code,
-                        "quantity": quantity - sell_qty,
-                        "current_price": latest_price,
-                    })
 
                 # LossTracker 업데이트 — 전량매도 시에만 (분할매도 이중 카운트 방지)
                 if sell_qty >= quantity:
diff --git a/backend/tests/test_portfolio_cache_bridge.py b/backend/tests/test_portfolio_cache_bridge.py
new file mode 100644
index 0000000..499c688
--- /dev/null
+++ b/backend/tests/test_portfolio_cache_bridge.py
@@ -0,0 +1,48 @@
+"""portfolio_cache_bridge: 매매 엔진 체결 → 포트폴리오 캐시/Portfolio 즉시 반영."""
+import asyncio
+from decimal import Decimal
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from app.api.endpoints.portfolio import portfolio_cache
+from app.models.models import Portfolio
+from app.services import portfolio_cache_bridge as bridge
+
+
+@pytest.fixture(autouse=True)
+def _reset_cache():
+    portfolio_cache.holdings = []
+    portfolio_cache.summary = {"available_cash": 1_000_000, "total_value": 0, "total_investment": 0,
+                               "total_assets": 1_000_000, "total_profit_loss": 0, "total_profit_loss_rate": 0, "total_stocks": 0}
+    portfolio_cache.recent_sells = {}
+    yield
+
+
+@pytest.mark.asyncio
+async def test_reflect_buy_then_sell_updates_cache_and_queues_db():
+    q = AsyncMock()
+    with patch("app.services.db_worker.enqueue_portfolio_upsert", q):
+        await bridge.reflect_buy("005930", "삼성전자", 3, 70000.0, strategy_type="daytrading")
+    h = portfolio_cache.holdings[0]
+    assert (h.stock_code, h.quantity, h.strategy_type) == ("005930", 3, "daytrading")
+    assert portfolio_cache.summary["available_cash"] == 1_000_000 - 210_000
+    assert q.await_args.args[0]["strategy_type"] == "daytrading"
+
+    # 부분 매도 → 잔량 반영, 전량 매도 → 목록에서 제거 + 최근매도 기록(동기화 되살림 방지)
+    with patch("app.services.db_worker.enqueue_portfolio_upsert", q):
+        await bridge.reflect_sell("005930", 1, 71000.0, remaining_qty=2)
+        assert portfolio_cache.holdings[0].quantity == 2
+        await bridge.reflect_sell("005930", 2, 71000.0, remaining_qty=0)
+    assert portfolio_cache.holdings == []
+    assert q.await_args.args[0]["quantity"] == 0
+    assert portfolio_cache.recently_sold_qty("005930") == 2
+
+
+@pytest.mark.asyncio
+async def test_reflect_sell_unknown_holding_does_not_zero_db():
+    """캐시에 없고 잔량도 모르면 DB 수량을 0으로 덮어쓰지 않는다."""
+    q = AsyncMock()
+    with patch("app.services.db_worker.enqueue_portfolio_upsert", q):
+        await bridge.reflect_sell("000660", 5, 100000.0)
+    q.assert_not_awaited()
diff --git a/frontend/src/hooks/useTradeActions.ts b/frontend/src/hooks/useTradeActions.ts
index 14f9920..9bf0f02 100644
--- a/frontend/src/hooks/useTradeActions.ts
+++ b/frontend/src/hooks/useTradeActions.ts
@@ -68,6 +68,15 @@ export const useTradeActions = () => {
                     : ''
                 toast.success(`${d.message || `${stockName} ${quantity}주 매도 주문 완료`}${pl}`)
 
+                // 낙관적 갱신: 서버 재조회 전에 화면에서 즉시 제거/차감
+                queryClient.setQueryData(['portfolio-combined', mode], (prev: any) => {
+                    if (!prev?.holdings) return prev
+                    const holdings = prev.holdings
+                        .map((h: any) => (h.stock_code === stockCode ? { ...h, quantity: h.quantity - quantity } : h))
+                        .filter((h: any) => h.quantity > 0)
+                    return { ...prev, holdings }
+                })
+
                 // Invalidate queries to refresh portfolio
                 queryClient.invalidateQueries({
                     queryKey: ['portfolio-combined'],