diff --git a/freqtrade/persistence.py b/freqtrade/persistence.py
index 20ae8c43a..aeab63f22 100644
--- a/freqtrade/persistence.py
+++ b/freqtrade/persistence.py
@@ -351,6 +351,7 @@ class Trade(_DECL_BASE):
         profit_percent = (close_trade_price / open_trade_price) - 1
         return float(f"{profit_percent:.8f}")
 
+    @staticmethod
     def calc_total_open_trades_in_stake_currency() -> float:
         """
         Calculates total invested amount in open trades