diff --git a/app/db.py b/app/db.py
index 0298be3..160816e 100644
--- a/app/db.py
+++ b/app/db.py
@@ -29,32 +29,36 @@ def init_db() -> None:
 
 
 def apply_safe_schema_patches() -> None:
-    """Tiny compatibility layer for the early MVP.
-
-    SQLAlchemy create_all creates missing tables but does not alter existing ones.
-    During rapid MVP iterations this keeps old server databases from breaking
-    when a new column is added.
-    """
     inspector = inspect(engine)
-    if 'bot_state' in inspector.get_table_names():
-        existing = {column['name'] for column in inspector.get_columns('bot_state')}
-        patches = []
-        if 'live_acknowledged' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN live_acknowledged BOOLEAN NOT NULL DEFAULT FALSE")
-        if 'emergency_stop' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN emergency_stop BOOLEAN NOT NULL DEFAULT FALSE")
-        if 'trade_mode' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN trade_mode VARCHAR(16) NOT NULL DEFAULT 'demo'")
-        if 'enabled' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN enabled BOOLEAN NOT NULL DEFAULT FALSE")
-        if 'trade_style_mode' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN trade_style_mode VARCHAR(32) NOT NULL DEFAULT 'balanced'")
-        if 'min_signal_score' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN min_signal_score FLOAT NOT NULL DEFAULT 65.0")
-        if 'max_open_positions' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN max_open_positions INTEGER NOT NULL DEFAULT 3")
-        if 'max_quote_per_trade' not in existing:
-            patches.append("ALTER TABLE bot_state ADD COLUMN max_quote_per_trade FLOAT NOT NULL DEFAULT 100.0")
-        with engine.begin() as conn:
-            for patch in patches:
-                conn.execute(text(patch))
+    table_names = inspector.get_table_names()
+    if 'bot_state' in table_names:
+        _add_missing_columns('bot_state', {
+            'live_acknowledged': "BOOLEAN NOT NULL DEFAULT FALSE",
+            'emergency_stop': "BOOLEAN NOT NULL DEFAULT FALSE",
+            'trade_mode': "VARCHAR(16) NOT NULL DEFAULT 'demo'",
+            'enabled': "BOOLEAN NOT NULL DEFAULT FALSE",
+            'trade_style_mode': "VARCHAR(32) NOT NULL DEFAULT 'balanced'",
+            'min_signal_score': "FLOAT NOT NULL DEFAULT 65.0",
+            'max_open_positions': "INTEGER NOT NULL DEFAULT 3",
+            'max_quote_per_trade': "FLOAT NOT NULL DEFAULT 100.0",
+        })
+    if 'demo_positions' in table_names:
+        _add_missing_columns('demo_positions', {
+            'side': "VARCHAR(8) NOT NULL DEFAULT 'long'",
+            'current_price': "FLOAT NOT NULL DEFAULT 0.0",
+            'take_profit': "FLOAT NOT NULL DEFAULT 0.0",
+            'stop_loss': "FLOAT NOT NULL DEFAULT 0.0",
+            'unrealized_pnl': "FLOAT NOT NULL DEFAULT 0.0",
+            'unrealized_pnl_pct': "FLOAT NOT NULL DEFAULT 0.0",
+            'opened_at': "TIMESTAMP WITH TIME ZONE DEFAULT NOW() NOT NULL",
+            'closed_at': "TIMESTAMP WITH TIME ZONE NULL",
+        })
+
+
+def _add_missing_columns(table_name: str, columns: dict[str, str]) -> None:
+    inspector = inspect(engine)
+    existing = {column['name'] for column in inspector.get_columns(table_name)}
+    with engine.begin() as conn:
+        for name, ddl in columns.items():
+            if name not in existing:
+                conn.execute(text(f'ALTER TABLE {table_name} ADD COLUMN {name} {ddl}'))