diff --git a/bot/data/db.py b/bot/data/db.py
index a4e4074..a364c2c 100644
--- a/bot/data/db.py
+++ b/bot/data/db.py
@@ -176,15 +176,18 @@ class Database:
         is computed in SQL so it matches the stored entry_price and shares exactly.
         """
         async with self._pool.acquire() as conn:
+            # $3 is cast on every use: Postgres cannot infer the parameter type
+            # from a bare "$3 IS NOT NULL" and fails the prepare with
+            # AmbiguousParameterError otherwise.
             await conn.execute("""
                 UPDATE trades
                 SET closed_at    = NOW(),
                     close_reason = $2,
-                    resolution   = $3,
+                    resolution   = $3::double precision,
                     close_pnl    = CASE
-                        WHEN $3 IS NOT NULL AND direction = 'BUY_YES'
+                        WHEN $3::double precision IS NOT NULL AND direction = 'BUY_YES'
                             THEN ($3::double precision - entry_price) * shares
-                        WHEN $3 IS NOT NULL AND direction = 'BUY_NO'
+                        WHEN $3::double precision IS NOT NULL AND direction = 'BUY_NO'
                             THEN ((1.0 - $3::double precision) - entry_price) * shares
                         ELSE NULL
                     END
diff --git a/bot/executor/paper.py b/bot/executor/paper.py
index bf2192f..2b75bbe 100644
--- a/bot/executor/paper.py
+++ b/bot/executor/paper.py
@@ -245,7 +245,7 @@ class PaperExecutor:
         if market_id not in self._portfolio.positions:
             return None
 
-        position_cost = self._portfolio.positions.pop(market_id)
+        position_cost = self._portfolio.positions[market_id]
         open_trades = await self._db.get_open_trades_for_market(market_id)
 
         if open_trades:
@@ -266,13 +266,17 @@ class PaperExecutor:
             payout = position_cost
             pnl = 0.0
 
-        self._portfolio.cash += payout
-
+        # Persist first, mutate memory after: if the DB write fails, the
+        # in-memory portfolio must keep the position so the next resolution
+        # check can retry the close.
         await self._db.close_paper_position(
             market_id,
             reason="resolved",
             resolution=resolution,
         )
+
+        self._portfolio.positions.pop(market_id)
+        self._portfolio.cash += payout
         log.info(
             "Closed position in %s, resolution=%.1f payout=$%.2f pnl=%+.2f",
             market_id, resolution, payout, pnl,
diff --git a/bot/main.py b/bot/main.py
index e2bcf10..217e4d4 100644
--- a/bot/main.py
+++ b/bot/main.py
@@ -58,9 +58,13 @@ async def check_resolutions(
         checked += 1
         if res is None or not res.resolved or res.resolution is None:
             continue
-        pnl = await executor.close_position(
-            market_id, res.resolution, question=pos.get("question") or "",
-        )
+        try:
+            pnl = await executor.close_position(
+                market_id, res.resolution, question=pos.get("question") or "",
+            )
+        except Exception as exc:
+            log.error("Failed to close resolved market %s: %s", market_id, exc)
+            continue
         resolved += 1
         log.info(
             "MARKET_RESOLVED market_id=%s resolution=%.1f pnl=%s | %s",
diff --git a/tests/test_paper_close.py b/tests/test_paper_close.py
index b497ad5..b833711 100644
--- a/tests/test_paper_close.py
+++ b/tests/test_paper_close.py
@@ -103,3 +103,28 @@ def test_unknown_market_returns_none():
         ex = PaperExecutor(db=FakeDB({}), bankroll=1000.0)
         return await ex.close_position("nope", 1.0)
     assert asyncio.run(run()) is None
+
+
+def test_db_failure_keeps_position_for_retry():
+    """Regression: a DB error during close must not mutate the in-memory
+    portfolio — otherwise the next resolution check skips the market
+    (not in positions) and the DB row stays open forever."""
+
+    class FailingDB(FakeDB):
+        async def close_paper_position(self, market_id, reason="", resolution=None):
+            raise RuntimeError("db down")
+
+    async def run():
+        db = FailingDB({
+            "mkt1": [{"direction": "BUY_YES", "shares": 200.0, "net_cost": 102.0}],
+        })
+        ex = PaperExecutor(db=db, bankroll=1000.0)
+        ex._portfolio.cash = 898.0
+        ex._portfolio.positions["mkt1"] = 100.0
+        with pytest.raises(RuntimeError):
+            await ex.close_position("mkt1", 1.0)
+        return ex
+
+    ex = asyncio.run(run())
+    assert ex._portfolio.positions == {"mkt1": 100.0}   # still open in memory
+    assert ex._portfolio.cash == pytest.approx(898.0)   # payout not credited