Validate stoploss_on_exchange_limit_ratio at startup time

freqtrade/exchange/exchange.py

@@ -386,6 +386,13 @@ class Exchange:
                 f'On exchange stoploss is not supported for {self.name}.'
             )
 
+        # Limit price threshold: As limit price should always be below stop-price
+        # Used for limit stoplosses on exchange
+        limit_price_pct = order_types.get('stoploss_on_exchange_limit_ratio', 0.99)
+        if limit_price_pct >= 1.0 or limit_price_pct <= 0.0:
+            raise OperationalException(
+                "stoploss_on_exchange_limit_ratio should be < 1.0 and > 0.0")
+
     def validate_order_time_in_force(self, order_time_in_force: Dict) -> None:
         """
         Checks if order time in force configured in strategy/config are supported