diff --git a/backend/app/main.py b/backend/app/main.py
index dcc5dd0..5b385d6 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -262,6 +262,52 @@ def _kis_stream_health_v2(application, now: float | None = None, market_open: bo
     return {"alive": alive, "last_msg_age": None if age is None else round(age, 1), "silent": silent}
 
 
+# 등록 0건 → 1건 이상으로 바뀐 시각(monotonic). 재구독 직후 옛 last_msg 로 오경보하지 않게 기준점으로 쓴다.
+_kis_stream_regs_since: float | None = None
+
+
+def _kis_stream_registrations_v2() -> int | None:
+    try:
+        from app.services.kis_realtime_stream import kis_stream
+        return len(kis_stream._registered)
+    except Exception as _swallowed:
+        warn_throttled(logger, "main:ks_regs", "[health] KIS 등록 수 확인 실패: %s", _swallowed)
+        return None
+
+
+def _kis_stream_health_v3(application, now: float | None = None, market_open: bool | None = None,
+                          registrations: int | None = -1) -> dict | None:
+    """v2 + 등록 0건이면 무수신을 정상으로 본다(2026-10-12).
+
+    스트림은 대시보드 구독 종목만 KIS 에 등록한다(매매 경로는 스트림을 쓰지 않는다).
+    브라우저가 닫혀 등록이 0건이면 수신이 없는 것이 정상인데, v2 는 이를 장중 무수신으로
+    error·텔레그램 경보했다(10/12 12:54·13:29·13:46 — 전부 구독 해제 10분 뒤).
+    태스크 사망은 등록 수와 무관하게 계속 silent 다. 등록 수를 알 수 없으면(None) v2 판정을 따른다.
+    """
+    global _kis_stream_regs_since
+    base = _kis_stream_health_v2(application, now=now, market_open=market_open)
+    if base is None:
+        return None
+    regs = _kis_stream_registrations_v2() if registrations == -1 else registrations
+    n = now if now is not None else time.monotonic()
+    base["registrations"] = regs
+    if regs is None:
+        return base
+    if regs <= 0:
+        _kis_stream_regs_since = None
+        if base["alive"]:
+            base["silent"] = False
+        return base
+    if _kis_stream_regs_since is None:
+        _kis_stream_regs_since = n
+    if base["silent"] and base["alive"]:
+        last = _kis_stream_last_msg_mono
+        ref = max(last if last is not None else -1e18, _kis_stream_regs_since)
+        base["silent"] = (n - ref) > float(_HB_KIS_STREAM_SILENT_SECONDS)
+        base["last_msg_age"] = round(n - ref, 1)
+    return base
+
+
 def _db_worker_health_v2(application) -> dict:
     task = getattr(application.state, "db_worker_task", None)
     try:
@@ -343,7 +389,7 @@ async def _heartbeat_watchdog_v2(application):
                 _notify_system_warning_bg(
                     "SCHEDULER", f"'{name}' 장중 사이클 정체 {info['last_cycle_age']}초 (alive={info['alive']})"
                 )
-            ks = _kis_stream_health_v2(application)
+            ks = _kis_stream_health_v3(application)
             if ks is None or not ks["silent"]:
                 _stale_alerted_at.pop("kis_stream", None)
             elif now - _stale_alerted_at.get("kis_stream", -1e9) >= realert:
@@ -1288,7 +1334,7 @@ def _runtime_health_v2(market_open: bool | None = None) -> tuple[dict, list]:
         detail["swing"] = "unavailable"
         reasons.append("swing_health_unavailable")
     try:
-        ks = _kis_stream_health_v2(app, market_open=market_open)
+        ks = _kis_stream_health_v3(app, market_open=market_open)
         if ks is not None:
             detail["kis_stream"] = ks
             if ks["silent"]:
diff --git a/backend/tests/test_main_kis_stream_regs_20261012.py b/backend/tests/test_main_kis_stream_regs_20261012.py
new file mode 100644
index 0000000..995e40f
--- /dev/null
+++ b/backend/tests/test_main_kis_stream_regs_20261012.py
@@ -0,0 +1,61 @@
+"""KIS 스트림 무수신 경보: 등록 0건(대시보드 미접속)은 정상 — 2026-10-12 운영 오경보 3건."""
+import app.main as m
+
+
+class _T:
+    def __init__(self, done):
+        self._d = done
+
+    def done(self):
+        return self._d
+
+
+class _App:
+    class state:
+        pass
+
+
+def _app(done=False):
+    a = _App()
+    a.state = type("S", (), {})()
+    a.state.kis_stream_task = _T(done)
+    return a
+
+
+def test_zero_registrations_is_not_silent(monkeypatch):
+    monkeypatch.setattr(m, "_kis_stream_last_msg_mono", 100.0)
+    monkeypatch.setattr(m, "_kis_stream_regs_since", None)
+    limit = m._HB_KIS_STREAM_SILENT_SECONDS
+    r = m._kis_stream_health_v3(_app(), now=100.0 + limit + 1, market_open=True, registrations=0)
+    assert r["silent"] is False and r["registrations"] == 0
+
+
+def test_dead_task_is_silent_even_with_zero_registrations(monkeypatch):
+    monkeypatch.setattr(m, "_kis_stream_last_msg_mono", 100.0)
+    monkeypatch.setattr(m, "_kis_stream_regs_since", None)
+    r = m._kis_stream_health_v3(_app(done=True), now=101.0, market_open=True, registrations=0)
+    assert r["silent"] is True
+
+
+def test_resubscribe_uses_registration_time_as_reference(monkeypatch):
+    limit = m._HB_KIS_STREAM_SILENT_SECONDS
+    monkeypatch.setattr(m, "_kis_stream_last_msg_mono", 100.0)
+    monkeypatch.setattr(m, "_kis_stream_regs_since", None)
+    t0 = 100.0 + limit + 500  # 옛 메시지 이후 오래 지나 재구독
+    assert m._kis_stream_health_v3(_app(), now=t0, market_open=True, registrations=8)["silent"] is False
+    assert m._kis_stream_health_v3(_app(), now=t0 + limit - 1, market_open=True, registrations=8)["silent"] is False
+    assert m._kis_stream_health_v3(_app(), now=t0 + limit + 1, market_open=True, registrations=8)["silent"] is True
+
+
+def test_registered_and_receiving_is_not_silent(monkeypatch):
+    limit = m._HB_KIS_STREAM_SILENT_SECONDS
+    monkeypatch.setattr(m, "_kis_stream_regs_since", 0.0)
+    monkeypatch.setattr(m, "_kis_stream_last_msg_mono", 1000.0)
+    assert m._kis_stream_health_v3(_app(), now=1000.0 + limit - 5, market_open=True, registrations=8)["silent"] is False
+
+
+def test_unknown_registrations_falls_back_to_v2(monkeypatch):
+    limit = m._HB_KIS_STREAM_SILENT_SECONDS
+    monkeypatch.setattr(m, "_kis_stream_last_msg_mono", 100.0)
+    monkeypatch.setattr(m, "_kis_stream_regs_since", None)
+    assert m._kis_stream_health_v3(_app(), now=100.0 + limit + 1, market_open=True, registrations=None)["silent"] is True