Avoid lookahead bias through informative pairs in callbacks

freqtrade/data/dataprovider.py

@@ -17,7 +17,7 @@ from freqtrade.constants import (FULL_DATAFRAME_THRESHOLD, Config, ListPairsWith
 from freqtrade.data.history import load_pair_history
 from freqtrade.enums import CandleType, RPCMessageType, RunMode
 from freqtrade.exceptions import ExchangeError, OperationalException
-from freqtrade.exchange import Exchange, timeframe_to_seconds
+from freqtrade.exchange import Exchange, timeframe_to_prev_date, timeframe_to_seconds
 from freqtrade.exchange.types import OrderBook
 from freqtrade.misc import append_candles_to_dataframe
 from freqtrade.rpc import RPCManager
@@ -46,6 +46,8 @@ class DataProvider:
         self.__rpc = rpc
         self.__cached_pairs: Dict[PairWithTimeframe, Tuple[DataFrame, datetime]] = {}
         self.__slice_index: Optional[int] = None
+        self.__slice_date: Optional[datetime] = None
+
         self.__cached_pairs_backtesting: Dict[PairWithTimeframe, DataFrame] = {}
         self.__producer_pairs_df: Dict[str,
                                        Dict[PairWithTimeframe, Tuple[DataFrame, datetime]]] = {}
@@ -64,10 +66,19 @@ class DataProvider:
     def _set_dataframe_max_index(self, limit_index: int):
         """
         Limit analyzed dataframe to max specified index.
+        Only relevant in backtesting.
         :param limit_index: dataframe index.
         """
         self.__slice_index = limit_index
 
+    def _set_dataframe_max_date(self, limit_date: datetime):
+        """
+        Limit infomrative dataframe to max specified index.
+        Only relevant in backtesting.
+        :param limit_date: "current date"
+        """
+        self.__slice_date = limit_date
+
     def _set_cached_df(
         self,
         pair: str,
@@ -356,6 +367,11 @@ class DataProvider:
             # Get historical OHLCV data (cached on disk).
             timeframe = timeframe or self._config['timeframe']
             data = self.historic_ohlcv(pair=pair, timeframe=timeframe, candle_type=candle_type)
+            # Cut date to timeframe-specific date.
+            # This is necessary to prevent lookahead bias in callbacks through informative pairs.
+            if self.__slice_date:
+                cutoff_date = timeframe_to_prev_date(timeframe, self.__slice_date)
+                data = data.loc[data['date'] < cutoff_date]
         if len(data) == 0:
             logger.warning(f"No data found for ({pair}, {timeframe}, {candle_type}).")
         return data

freqtrade/optimize/backtesting.py

@@ -1229,12 +1229,14 @@ class Backtesting:
                     is_first = True
                     current_time_det = current_time
                     for det_row in detail_data[HEADERS].values.tolist():
+                        self.dataprovider._set_dataframe_max_date(current_time_det)
                         open_trade_count_start = self.backtest_loop(
                             det_row, pair, current_time_det, end_date,
                             open_trade_count_start, trade_dir, is_first)
                         current_time_det += timedelta(minutes=self.timeframe_detail_min)
                         is_first = False
                 else:
+                    self.dataprovider._set_dataframe_max_date(current_time)
                     open_trade_count_start = self.backtest_loop(
                         row, pair, current_time, end_date,
                         open_trade_count_start, trade_dir)