diff --git a/src/main.py b/src/main.py
index 14c8e40..3b652bb 100644
--- a/src/main.py
+++ b/src/main.py
@@ -581,6 +581,11 @@ async def trading_cycle(
     if candidate:
         market_data["rsi"] = candidate.rsi
         market_data["volume_ratio"] = candidate.volume_ratio
+    else:
+        # Holding stocks not in scanner: derive implied RSI from price change,
+        # volume_ratio defaults to 1.0 (no surge data available).
+        market_data["rsi"] = max(0.0, min(100.0, 50.0 + price_change_pct * 2.0))
+        market_data["volume_ratio"] = 1.0
 
     # Enrich market_data with holding info for SELL/HOLD scenario conditions
     open_pos = get_open_position(db_conn, stock_code, market.code)
@@ -1499,8 +1504,9 @@ async def run_daily_session(
                 active_stocks={},
             )
             if not fallback_stocks:
-                logger.warning(
-                    "No dynamic overseas symbol universe for %s; scanner cannot run",
+                logger.debug(
+                    "No dynamic overseas symbol universe for %s;"
+                    " scanner will use overseas ranking API",
                     market.code,
                 )
         try:
@@ -2812,9 +2818,9 @@ async def run(settings: Settings) -> None:
                                     active_stocks=active_stocks,
                                 )
                                 if not fallback_stocks:
-                                    logger.warning(
+                                    logger.debug(
                                         "No dynamic overseas symbol universe for %s;"
-                                        " scanner cannot run",
+                                        " scanner will use overseas ranking API",
                                         market.code,
                                     )
 
diff --git a/tests/test_main.py b/tests/test_main.py
index a8a0aa7..3f15a00 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1668,10 +1668,10 @@ class TestScenarioEngineIntegration:
                 scan_candidates={"US": {"005930": us_candidate}},  # Wrong market
             )
 
-        # Should NOT have rsi/volume_ratio because candidate is under US, not KR
+        # Should NOT use US candidate's rsi (=15.0); fallback implied_rsi used instead
         market_data = engine.evaluate.call_args[0][2]
-        assert "rsi" not in market_data
-        assert "volume_ratio" not in market_data
+        assert market_data["rsi"] != 15.0  # US candidate's rsi must be ignored
+        assert market_data["volume_ratio"] == 1.0  # Fallback default
 
     @pytest.mark.asyncio
     async def test_scenario_engine_called_without_scanner_data(
@@ -1702,11 +1702,13 @@ class TestScenarioEngineIntegration:
                 scan_candidates={},  # No scanner data
             )
 
-        # Should still work, just without rsi/volume_ratio
+        # Holding stocks without scanner data use implied_rsi (from price_change_pct)
+        # and volume_ratio=1.0 as fallback, so rsi/volume_ratio are always present.
         engine.evaluate.assert_called_once()
         market_data = engine.evaluate.call_args[0][2]
-        assert "rsi" not in market_data
-        assert "volume_ratio" not in market_data
+        assert "rsi" in market_data  # Implied RSI from price_change_pct=2.5 → 55.0
+        assert market_data["rsi"] == pytest.approx(55.0)
+        assert market_data["volume_ratio"] == 1.0
         assert market_data["current_price"] == 50000.0
 
     @pytest.mark.asyncio