diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 0acd10900..20a0c7e69 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -130,11 +130,8 @@ class Exchange:
         self._trades_pagination = self._ft_has['trades_pagination']
         self._trades_pagination_arg = self._ft_has['trades_pagination_arg']
 
-        self.trading_mode: TradingMode = (
-            TradingMode(config.get('trading_mode'))
-            if config.get('trading_mode')
-            else TradingMode.SPOT
-        )
+        self.trading_mode = TradingMode(config.get('trading_mode', 'spot'))
+
         self.collateral: Optional[Collateral] = (
             Collateral(config.get('collateral'))
             if config.get('collateral')
diff --git a/freqtrade/freqtradebot.py b/freqtrade/freqtradebot.py
index 4fd6d9b1b..708635991 100644
--- a/freqtrade/freqtradebot.py
+++ b/freqtrade/freqtradebot.py
@@ -106,12 +106,9 @@ class FreqtradeBot(LoggingMixin):
         self._exit_lock = Lock()
         LoggingMixin.__init__(self, logger, timeframe_to_seconds(self.strategy.timeframe))
 
-        self.trading_mode: TradingMode = TradingMode.SPOT
+        self.trading_mode = TradingMode(self.config.get('trading_mode', 'spot'))
+
         self.collateral_type: Optional[Collateral] = None
-
-        if 'trading_mode' in self.config:
-            self.trading_mode = TradingMode(self.config['trading_mode'])
-
         if 'collateral_type' in self.config:
             self.collateral_type = Collateral(self.config['collateral_type'])
 
diff --git a/freqtrade/optimize/backtesting.py b/freqtrade/optimize/backtesting.py
index 678ff1b32..26408e341 100644
--- a/freqtrade/optimize/backtesting.py
+++ b/freqtrade/optimize/backtesting.py
@@ -18,6 +18,7 @@ from freqtrade.data.btanalysis import trade_list_to_dataframe
 from freqtrade.data.converter import trim_dataframe, trim_dataframes
 from freqtrade.data.dataprovider import DataProvider
 from freqtrade.enums import BacktestState, SellType
+from freqtrade.enums.tradingmode import TradingMode
 from freqtrade.exceptions import DependencyException, OperationalException
 from freqtrade.exchange import timeframe_to_minutes, timeframe_to_seconds
 from freqtrade.mixins import LoggingMixin
@@ -122,7 +123,8 @@ class Backtesting:
 
         # TODO-lev: This should come from the configuration setting or better a
         # TODO-lev: combination of config/strategy "use_shorts"(?) and "can_short" from the exchange
-        self._can_short = False
+        self.trading_mode = TradingMode(config.get('trading_mode', 'spot'))
+        self._can_short = self.trading_mode == TradingMode.MARGIN
 
         self.progress = BTProgress()
         self.abort = False