diff --git a/backend/main.py b/backend/main.py
index 24079d2..27505d1 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -488,3 +488,83 @@ async def collector_health(user: dict = Depends(get_current_user)):
         pass
     conn.close()
     return {"collector": status, "timestamp": now_ms}
+
+
+# ─── V5 Signal Engine API ────────────────────────────────────────
+
+@app.get("/api/signals/indicators")
+async def get_signal_indicators(
+    symbol: str = "BTC",
+    minutes: int = 60,
+    user: dict = Depends(get_current_user),
+):
+    """获取signal_indicators_1m数据（前端图表用）"""
+    sym_full = symbol.upper() + "USDT"
+    now_ms = int(time.time() * 1000)
+    start_ms = now_ms - minutes * 60 * 1000
+
+    conn = sqlite3.connect(DB_PATH)
+    conn.row_factory = sqlite3.Row
+    try:
+        rows = conn.execute(
+            "SELECT ts, cvd_fast, cvd_mid, cvd_day, atr_5m, vwap_30m, price, score, signal "
+            "FROM signal_indicators_1m WHERE symbol = ? AND ts >= ? ORDER BY ts ASC",
+            (sym_full, start_ms)
+        ).fetchall()
+    except Exception:
+        rows = []
+    conn.close()
+    return {
+        "symbol": symbol,
+        "count": len(rows),
+        "data": [dict(r) for r in rows],
+    }
+
+
+@app.get("/api/signals/latest")
+async def get_signal_latest(
+    user: dict = Depends(get_current_user),
+):
+    """获取最新一条各symbol的指标快照"""
+    conn = sqlite3.connect(DB_PATH)
+    conn.row_factory = sqlite3.Row
+    result = {}
+    for sym in ["BTCUSDT", "ETHUSDT"]:
+        try:
+            row = conn.execute(
+                "SELECT ts, cvd_fast, cvd_mid, cvd_day, cvd_fast_slope, atr_5m, atr_percentile, "
+                "vwap_30m, price, p95_qty, p99_qty, score, signal "
+                "FROM signal_indicators WHERE symbol = ? ORDER BY ts DESC LIMIT 1",
+                (sym,)
+            ).fetchone()
+            if row:
+                result[sym.replace("USDT", "")] = dict(row)
+        except Exception:
+            pass
+    conn.close()
+    return result
+
+
+@app.get("/api/signals/trades")
+async def get_signal_trades(
+    status: str = "all",
+    limit: int = 50,
+    user: dict = Depends(get_current_user),
+):
+    """获取信号交易记录"""
+    conn = sqlite3.connect(DB_PATH)
+    conn.row_factory = sqlite3.Row
+    try:
+        if status == "all":
+            rows = conn.execute(
+                "SELECT * FROM signal_trades ORDER BY ts_open DESC LIMIT ?", (limit,)
+            ).fetchall()
+        else:
+            rows = conn.execute(
+                "SELECT * FROM signal_trades WHERE status = ? ORDER BY ts_open DESC LIMIT ?",
+                (status, limit)
+            ).fetchall()
+    except Exception:
+        rows = []
+    conn.close()
+    return {"count": len(rows), "data": [dict(r) for r in rows]}
diff --git a/backend/signal_engine.py b/backend/signal_engine.py
new file mode 100644
index 0000000..c66b833
--- /dev/null
+++ b/backend/signal_engine.py
@@ -0,0 +1,554 @@
+"""
+signal_engine.py — V5 短线交易信号引擎
+
+架构：
+  - 独立PM2进程，每5秒循环
+  - 内存滚动窗口计算指标（CVD/ATR/VWAP/大单阈值）
+  - 启动时回灌历史数据（冷启动warmup）
+  - 信号评估：核心3条件+加分3条件
+  - 输出：signal_indicators表 + signal_trades表 + Discord推送
+
+指标：
+  - CVD_fast (30m滚动) / CVD_mid (4h滚动) / CVD_day (UTC日内)
+  - ATR (5m, 14周期)
+  - VWAP_30m
+  - 大单阈值 P95/P99 (24h滚动)
+"""
+
+import logging
+import os
+import sqlite3
+import time
+import math
+import statistics
+from collections import deque
+from datetime import datetime, timezone
+from typing import Optional
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+    handlers=[
+        logging.StreamHandler(),
+        logging.FileHandler(os.path.join(os.path.dirname(__file__), "..", "signal-engine.log")),
+    ],
+)
+logger = logging.getLogger("signal-engine")
+
+DB_PATH = os.path.join(os.path.dirname(__file__), "..", "arb.db")
+SYMBOLS = ["BTCUSDT", "ETHUSDT"]
+LOOP_INTERVAL = 5  # 秒
+
+# 窗口大小（毫秒）
+WINDOW_FAST = 30 * 60 * 1000      # 30分钟
+WINDOW_MID = 4 * 3600 * 1000      # 4小时
+WINDOW_DAY = 24 * 3600 * 1000     # 24小时（用于P95/P99计算）
+WINDOW_VWAP = 30 * 60 * 1000      # 30分钟
+
+# ATR参数
+ATR_PERIOD_MS = 5 * 60 * 1000     # 5分钟K线
+ATR_LENGTH = 14                    # 14根
+
+# 信号冷却
+COOLDOWN_MS = 10 * 60 * 1000      # 10分钟
+
+
+# ─── DB helpers ──────────────────────────────────────────────────
+
+def get_conn() -> sqlite3.Connection:
+    conn = sqlite3.connect(DB_PATH, timeout=30)
+    conn.row_factory = sqlite3.Row
+    conn.execute("PRAGMA journal_mode=WAL")
+    conn.execute("PRAGMA synchronous=NORMAL")
+    return conn
+
+
+def init_tables(conn: sqlite3.Connection):
+    conn.execute("""
+        CREATE TABLE IF NOT EXISTS signal_indicators (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            ts INTEGER NOT NULL,
+            symbol TEXT NOT NULL,
+            cvd_fast REAL,
+            cvd_mid REAL,
+            cvd_day REAL,
+            cvd_fast_slope REAL,
+            atr_5m REAL,
+            atr_percentile REAL,
+            vwap_30m REAL,
+            price REAL,
+            p95_qty REAL,
+            p99_qty REAL,
+            buy_vol_1m REAL,
+            sell_vol_1m REAL,
+            score INTEGER,
+            signal TEXT
+        )
+    """)
+    conn.execute("CREATE INDEX IF NOT EXISTS idx_si_ts ON signal_indicators(ts)")
+    conn.execute("CREATE INDEX IF NOT EXISTS idx_si_sym_ts ON signal_indicators(symbol, ts)")
+
+    conn.execute("""
+        CREATE TABLE IF NOT EXISTS signal_indicators_1m (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            ts INTEGER NOT NULL,
+            symbol TEXT NOT NULL,
+            cvd_fast REAL,
+            cvd_mid REAL,
+            cvd_day REAL,
+            atr_5m REAL,
+            vwap_30m REAL,
+            price REAL,
+            score INTEGER,
+            signal TEXT
+        )
+    """)
+    conn.execute("CREATE INDEX IF NOT EXISTS idx_si1m_sym_ts ON signal_indicators_1m(symbol, ts)")
+
+    conn.execute("""
+        CREATE TABLE IF NOT EXISTS signal_trades (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            ts_open INTEGER NOT NULL,
+            ts_close INTEGER,
+            symbol TEXT NOT NULL,
+            direction TEXT NOT NULL,
+            entry_price REAL,
+            exit_price REAL,
+            qty REAL,
+            score INTEGER,
+            pnl REAL,
+            sl_price REAL,
+            tp1_price REAL,
+            tp2_price REAL,
+            status TEXT DEFAULT 'open'
+        )
+    """)
+    conn.commit()
+
+
+# ─── 滚动窗口 ───────────────────────────────────────────────────
+
+class TradeWindow:
+    """滚动时间窗口，维护买卖量和价格数据"""
+
+    def __init__(self, window_ms: int):
+        self.window_ms = window_ms
+        self.trades: deque = deque()  # (time_ms, qty, price, is_buyer_maker)
+        self.buy_vol = 0.0
+        self.sell_vol = 0.0
+        self.pq_sum = 0.0  # price * qty 累加（VWAP用）
+        self.q_sum = 0.0   # qty累加
+        self.quantities: list = []  # 用于P95/P99（仅24h窗口用）
+
+    def add(self, time_ms: int, qty: float, price: float, is_buyer_maker: int):
+        self.trades.append((time_ms, qty, price, is_buyer_maker))
+        pq = price * qty
+        self.pq_sum += pq
+        self.q_sum += qty
+        if is_buyer_maker == 0:
+            self.buy_vol += qty
+        else:
+            self.sell_vol += qty
+
+    def trim(self, now_ms: int):
+        cutoff = now_ms - self.window_ms
+        while self.trades and self.trades[0][0] < cutoff:
+            t_ms, qty, price, ibm = self.trades.popleft()
+            pq = price * qty
+            self.pq_sum -= pq
+            self.q_sum -= qty
+            if ibm == 0:
+                self.buy_vol -= qty
+            else:
+                self.sell_vol -= qty
+
+    @property
+    def cvd(self) -> float:
+        return self.buy_vol - self.sell_vol
+
+    @property
+    def vwap(self) -> float:
+        return self.pq_sum / self.q_sum if self.q_sum > 0 else 0.0
+
+    @property
+    def total_vol(self) -> float:
+        return self.buy_vol + self.sell_vol
+
+
+class ATRCalculator:
+    """5分钟K线ATR计算"""
+
+    def __init__(self, period_ms: int = ATR_PERIOD_MS, length: int = ATR_LENGTH):
+        self.period_ms = period_ms
+        self.length = length
+        self.candles: deque = deque(maxlen=length + 1)
+        self.current_candle: Optional[dict] = None
+        self.atr_history: deque = deque(maxlen=288)  # 24h of 5m candles for percentile
+
+    def update(self, time_ms: int, price: float):
+        bar_ms = (time_ms // self.period_ms) * self.period_ms
+        if self.current_candle is None or self.current_candle["bar"] != bar_ms:
+            if self.current_candle is not None:
+                self.candles.append(self.current_candle)
+            self.current_candle = {
+                "bar": bar_ms, "open": price, "high": price, "low": price, "close": price
+            }
+        else:
+            c = self.current_candle
+            c["high"] = max(c["high"], price)
+            c["low"] = min(c["low"], price)
+            c["close"] = price
+
+    @property
+    def atr(self) -> float:
+        if len(self.candles) < 2:
+            return 0.0
+        trs = []
+        candles_list = list(self.candles)
+        for i in range(1, len(candles_list)):
+            prev_close = candles_list[i-1]["close"]
+            c = candles_list[i]
+            tr = max(c["high"] - c["low"], abs(c["high"] - prev_close), abs(c["low"] - prev_close))
+            trs.append(tr)
+        if not trs:
+            return 0.0
+        # EMA-style ATR
+        atr_val = trs[0]
+        for tr in trs[1:]:
+            atr_val = (atr_val * (self.length - 1) + tr) / self.length
+        return atr_val
+
+    @property
+    def atr_percentile(self) -> float:
+        """当前ATR在最近24h中的分位数"""
+        current = self.atr
+        if current == 0:
+            return 50.0
+        self.atr_history.append(current)
+        if len(self.atr_history) < 10:
+            return 50.0
+        sorted_hist = sorted(self.atr_history)
+        rank = sum(1 for x in sorted_hist if x <= current)
+        return (rank / len(sorted_hist)) * 100
+
+
+class SymbolState:
+    """单个交易对的完整状态"""
+
+    def __init__(self, symbol: str):
+        self.symbol = symbol
+        self.win_fast = TradeWindow(WINDOW_FAST)
+        self.win_mid = TradeWindow(WINDOW_MID)
+        self.win_day = TradeWindow(WINDOW_DAY)
+        self.win_vwap = TradeWindow(WINDOW_VWAP)
+        self.atr_calc = ATRCalculator()
+        self.last_processed_id = 0
+        self.warmup = True
+        self.warmup_until = 0
+        self.prev_cvd_fast = 0.0
+        self.last_signal_ts = 0
+        self.last_signal_dir = ""
+        # P99大单追踪（最近15分钟）
+        self.recent_large_trades: deque = deque()  # (time_ms, qty, is_buyer_maker)
+
+    def process_trade(self, agg_id: int, time_ms: int, price: float, qty: float, is_buyer_maker: int):
+        now_ms = time_ms
+        self.win_fast.add(time_ms, qty, price, is_buyer_maker)
+        self.win_mid.add(time_ms, qty, price, is_buyer_maker)
+        self.win_day.add(time_ms, qty, price, is_buyer_maker)
+        self.win_vwap.add(time_ms, qty, price, is_buyer_maker)
+        self.atr_calc.update(time_ms, price)
+
+        self.win_fast.trim(now_ms)
+        self.win_mid.trim(now_ms)
+        self.win_day.trim(now_ms)
+        self.win_vwap.trim(now_ms)
+
+        self.last_processed_id = agg_id
+
+    def compute_p95_p99(self) -> tuple[float, float]:
+        """从24h窗口计算大单阈值"""
+        if len(self.win_day.trades) < 100:
+            return 5.0, 10.0  # 默认兜底
+
+        qtys = [t[1] for t in self.win_day.trades]
+        qtys.sort()
+        n = len(qtys)
+        p95 = qtys[int(n * 0.95)]
+        p99 = qtys[int(n * 0.99)]
+
+        # BTC兜底5，ETH兜底50
+        if "BTC" in self.symbol:
+            p95 = max(p95, 5.0)
+            p99 = max(p99, 10.0)
+        else:
+            p95 = max(p95, 50.0)
+            p99 = max(p99, 100.0)
+        return p95, p99
+
+    def update_large_trades(self, now_ms: int, p99: float):
+        """更新最近15分钟的P99大单记录"""
+        cutoff = now_ms - 15 * 60 * 1000
+        while self.recent_large_trades and self.recent_large_trades[0][0] < cutoff:
+            self.recent_large_trades.popleft()
+
+        # 从最近处理的trades中找大单
+        for t in self.win_fast.trades:
+            if t[1] >= p99 and t[0] > cutoff:
+                self.recent_large_trades.append((t[0], t[1], t[3]))
+
+    def evaluate_signal(self, now_ms: int) -> dict:
+        """评估信号：核心3条件 + 加分3条件"""
+        cvd_fast = self.win_fast.cvd
+        cvd_mid = self.win_mid.cvd
+        vwap = self.win_vwap.vwap
+        atr = self.atr_calc.atr
+        atr_pct = self.atr_calc.atr_percentile
+        p95, p99 = self.compute_p95_p99()
+        self.update_large_trades(now_ms, p99)
+
+        # 当前价格（用VWAP近似）
+        price = vwap if vwap > 0 else 0
+
+        # CVD_fast斜率
+        cvd_fast_slope = cvd_fast - self.prev_cvd_fast
+        self.prev_cvd_fast = cvd_fast
+
+        result = {
+            "cvd_fast": cvd_fast,
+            "cvd_mid": cvd_mid,
+            "cvd_day": self.win_day.cvd,
+            "cvd_fast_slope": cvd_fast_slope,
+            "atr": atr,
+            "atr_pct": atr_pct,
+            "vwap": vwap,
+            "price": price,
+            "p95": p95,
+            "p99": p99,
+            "signal": None,
+            "direction": None,
+            "score": 0,
+        }
+
+        if self.warmup or price == 0 or atr == 0:
+            return result
+
+        # 冷却期检查
+        if now_ms - self.last_signal_ts < COOLDOWN_MS:
+            return result
+
+        # === 核心条件 ===
+        # 做多
+        long_core = (
+            cvd_fast > 0 and cvd_fast_slope > 0 and  # CVD_fast正且上升
+            cvd_mid > 0 and                            # CVD_mid正
+            price > vwap                               # 价格在VWAP上方
+        )
+        # 做空
+        short_core = (
+            cvd_fast < 0 and cvd_fast_slope < 0 and
+            cvd_mid < 0 and
+            price < vwap
+        )
+
+        if not long_core and not short_core:
+            return result
+
+        direction = "LONG" if long_core else "SHORT"
+
+        # === 加分条件 ===
+        score = 0
+
+        # 1. ATR压缩→扩张 (+25)
+        if atr_pct > 60:
+            score += 25
+
+        # 2. 无反向P99大单 (+20)
+        has_adverse_large = False
+        for lt in self.recent_large_trades:
+            if direction == "LONG" and lt[2] == 1:  # 大卖单对多头不利
+                has_adverse_large = True
+            elif direction == "SHORT" and lt[2] == 0:  # 大买单对空头不利
+                has_adverse_large = True
+        if not has_adverse_large:
+            score += 20
+
+        # 3. 资金费率配合 (+15) — 从rate_snapshots读取
+        # 暂时跳过，后续接入
+        # TODO: 接入资金费率条件
+        score += 0  # placeholder
+
+        result["signal"] = direction
+        result["direction"] = direction
+        result["score"] = score
+
+        # 更新冷却
+        self.last_signal_ts = now_ms
+        self.last_signal_dir = direction
+
+        return result
+
+
+# ─── 主循环 ──────────────────────────────────────────────────────
+
+def get_month_tables(conn: sqlite3.Connection) -> list[str]:
+    rows = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name LIKE 'agg_trades_2%' ORDER BY name"
+    ).fetchall()
+    return [r["name"] for r in rows]
+
+
+def load_historical(conn: sqlite3.Connection, state: SymbolState, window_ms: int):
+    """冷启动：回灌历史数据到内存窗口"""
+    now_ms = int(time.time() * 1000)
+    start_ms = now_ms - window_ms
+    tables = get_month_tables(conn)
+
+    count = 0
+    for tname in tables:
+        try:
+            rows = conn.execute(
+                f"SELECT agg_id, price, qty, time_ms, is_buyer_maker FROM {tname} "
+                f"WHERE symbol = ? AND time_ms >= ? ORDER BY agg_id ASC",
+                (state.symbol, start_ms)
+            ).fetchall()
+            for r in rows:
+                state.process_trade(r["agg_id"], r["time_ms"], r["price"], r["qty"], r["is_buyer_maker"])
+                count += 1
+        except Exception as e:
+            logger.warning(f"Error loading {tname}: {e}")
+
+    logger.info(f"[{state.symbol}] 冷启动完成: 加载{count:,}条历史数据 (窗口={window_ms//3600000}h)")
+    state.warmup = False
+
+
+def fetch_new_trades(conn: sqlite3.Connection, symbol: str, last_id: int) -> list:
+    """增量读取新aggTrades"""
+    tables = get_month_tables(conn)
+    results = []
+    for tname in tables[-2:]:  # 只查最近两个月表
+        try:
+            rows = conn.execute(
+                f"SELECT agg_id, price, qty, time_ms, is_buyer_maker FROM {tname} "
+                f"WHERE symbol = ? AND agg_id > ? ORDER BY agg_id ASC LIMIT 10000",
+                (symbol, last_id)
+            ).fetchall()
+            results.extend(rows)
+        except Exception:
+            pass
+    return results
+
+
+def save_indicator(conn: sqlite3.Connection, ts: int, symbol: str, result: dict):
+    conn.execute("""
+        INSERT INTO signal_indicators
+        (ts, symbol, cvd_fast, cvd_mid, cvd_day, cvd_fast_slope, atr_5m, atr_percentile,
+         vwap_30m, price, p95_qty, p99_qty, score, signal)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+    """, (
+        ts, symbol,
+        result["cvd_fast"], result["cvd_mid"], result["cvd_day"], result["cvd_fast_slope"],
+        result["atr"], result["atr_pct"],
+        result["vwap"], result["price"],
+        result["p95"], result["p99"],
+        result["score"], result.get("signal")
+    ))
+    conn.commit()
+
+
+def save_indicator_1m(conn: sqlite3.Connection, ts: int, symbol: str, result: dict):
+    """每分钟聚合保存"""
+    bar_ts = (ts // 60000) * 60000
+    existing = conn.execute(
+        "SELECT id FROM signal_indicators_1m WHERE ts = ? AND symbol = ?", (bar_ts, symbol)
+    ).fetchone()
+    if existing:
+        conn.execute("""
+            UPDATE signal_indicators_1m SET
+                cvd_fast=?, cvd_mid=?, cvd_day=?, atr_5m=?, vwap_30m=?, price=?, score=?, signal=?
+            WHERE ts=? AND symbol=?
+        """, (
+            result["cvd_fast"], result["cvd_mid"], result["cvd_day"],
+            result["atr"], result["vwap"], result["price"],
+            result["score"], result.get("signal"),
+            bar_ts, symbol
+        ))
+    else:
+        conn.execute("""
+            INSERT INTO signal_indicators_1m
+            (ts, symbol, cvd_fast, cvd_mid, cvd_day, atr_5m, vwap_30m, price, score, signal)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        """, (
+            bar_ts, symbol,
+            result["cvd_fast"], result["cvd_mid"], result["cvd_day"],
+            result["atr"], result["vwap"], result["price"],
+            result["score"], result.get("signal")
+        ))
+    conn.commit()
+
+
+def main():
+    conn = get_conn()
+    init_tables(conn)
+
+    states = {sym: SymbolState(sym) for sym in SYMBOLS}
+
+    # 冷启动：回灌4h数据
+    for sym, state in states.items():
+        load_historical(conn, state, WINDOW_MID)
+
+    logger.info("=== Signal Engine 启动完成 ===")
+
+    last_1m_save = {}
+    cycle = 0
+
+    while True:
+        try:
+            now_ms = int(time.time() * 1000)
+
+            for sym, state in states.items():
+                # 增量读取新数据
+                new_trades = fetch_new_trades(conn, sym, state.last_processed_id)
+                for t in new_trades:
+                    state.process_trade(t["agg_id"], t["time_ms"], t["price"], t["qty"], t["is_buyer_maker"])
+
+                # 评估信号
+                result = state.evaluate_signal(now_ms)
+
+                # 保存5秒指标
+                save_indicator(conn, now_ms, sym, result)
+
+                # 每分钟保存聚合
+                bar_1m = (now_ms // 60000) * 60000
+                if last_1m_save.get(sym) != bar_1m:
+                    save_indicator_1m(conn, now_ms, sym, result)
+                    last_1m_save[sym] = bar_1m
+
+                # 有信号则记录
+                if result.get("signal"):
+                    logger.info(
+                        f"[{sym}] 🚨 信号: {result['signal']} "
+                        f"score={result['score']} price={result['price']:.1f} "
+                        f"CVD_fast={result['cvd_fast']:.1f} CVD_mid={result['cvd_mid']:.1f}"
+                    )
+                    # TODO: Discord推送
+                    # TODO: 写入signal_trades
+
+            cycle += 1
+            if cycle % 60 == 0:  # 每5分钟打一次状态
+                for sym, state in states.items():
+                    r = state.evaluate_signal(now_ms)
+                    logger.info(
+                        f"[{sym}] 状态: CVD_fast={r['cvd_fast']:.1f} CVD_mid={r['cvd_mid']:.1f} "
+                        f"ATR={r['atr']:.2f}({r['atr_pct']:.0f}%) VWAP={r['vwap']:.1f} "
+                        f"P95={r['p95']:.4f} P99={r['p99']:.4f}"
+                    )
+
+        except Exception as e:
+            logger.error(f"循环异常: {e}", exc_info=True)
+
+        time.sleep(LOOP_INTERVAL)
+
+
+if __name__ == "__main__":
+    main()