From be770a89417b90a82d537ac5f26d2d76ee726a76 Mon Sep 17 00:00:00 2001
From: gbojen <gbojen@kpmg.com>
Date: Tue, 6 Apr 2021 10:42:53 +0200
Subject: [PATCH] added VolatilityFilter resolves freqtrade#4650

---
 freqtrade/constants.py                        |   2 +-
 .../plugins/pairlist/VolatilityFilter.py      | 120 ++++++++++++++++++
 2 files changed, 121 insertions(+), 1 deletion(-)
 create mode 100644 freqtrade/plugins/pairlist/VolatilityFilter.py

diff --git a/freqtrade/constants.py b/freqtrade/constants.py
index 3a2ed98e9..b98161ff2 100644
--- a/freqtrade/constants.py
+++ b/freqtrade/constants.py
@@ -26,7 +26,7 @@ HYPEROPT_LOSS_BUILTIN = ['ShortTradeDurHyperOptLoss', 'OnlyProfitHyperOptLoss',
 AVAILABLE_PAIRLISTS = ['StaticPairList', 'VolumePairList',
                        'AgeFilter', 'PerformanceFilter', 'PrecisionFilter',
                        'PriceFilter', 'RangeStabilityFilter', 'ShuffleFilter',
-                       'SpreadFilter']
+                       'SpreadFilter', 'VolatilityFilter']
 AVAILABLE_PROTECTIONS = ['CooldownPeriod', 'LowProfitPairs', 'MaxDrawdown', 'StoplossGuard']
 AVAILABLE_DATAHANDLERS = ['json', 'jsongz', 'hdf5']
 DRY_RUN_WALLET = 1000
diff --git a/freqtrade/plugins/pairlist/VolatilityFilter.py b/freqtrade/plugins/pairlist/VolatilityFilter.py
new file mode 100644
index 000000000..97e86bab6
--- /dev/null
+++ b/freqtrade/plugins/pairlist/VolatilityFilter.py
@@ -0,0 +1,120 @@
+"""
+Rate of change pairlist filter
+"""
+import logging
+from copy import deepcopy
+from typing import Any, Dict, List, Optional
+
+import sys
+import arrow
+from cachetools.ttl import TTLCache
+from pandas import DataFrame
+import numpy as np
+
+from freqtrade.exceptions import OperationalException
+from freqtrade.misc import plural
+from freqtrade.plugins.pairlist.IPairList import IPairList
+
+
+
+logger = logging.getLogger(__name__)
+
+
+class VolatilityFilter(IPairList):
+    '''
+    Filters pairs by volatility
+    '''
+
+    def __init__(self, exchange, pairlistmanager,
+                 config: Dict[str, Any], pairlistconfig: Dict[str, Any],
+                 pairlist_pos: int) -> None:
+        super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)
+
+        self._days = pairlistconfig.get('lookback_days', 10)
+        self._min_volatility = pairlistconfig.get('min_volatility', 0)
+        self._max_volatility = pairlistconfig.get('max_volatility', sys.maxsize)
+        self._refresh_period = pairlistconfig.get('refresh_period', 1440)
+
+        self._pair_cache: TTLCache = TTLCache(maxsize=1000, ttl=self._refresh_period)
+
+        if self._days < 1:
+            raise OperationalException("VolatilityFilter requires lookback_days to be >= 1")
+        if self._days > exchange.ohlcv_candle_limit('1d'):
+            raise OperationalException("VolatilityFilter requires lookback_days to not "
+                                       "exceed exchange max request size "
+                                       f"({exchange.ohlcv_candle_limit('1d')})")
+
+    @property
+    def needstickers(self) -> bool:
+        """
+        Boolean property defining if tickers are necessary.
+        If no Pairlist requires tickers, an empty List is passed
+        as tickers argument to filter_pairlist
+        """
+        return False
+
+    def short_desc(self) -> str:
+        """
+        Short whitelist method description - used for startup-messages
+        """
+        return (f"{self.name} - Filtering pairs with volatility range "
+                f"{self._min_volatility}-{self._max_volatility} the last {self._days} {plural(self._days, 'day')}.")
+
+    def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
+        """
+        Validate trading range
+        :param pairlist: pairlist to filter or sort
+        :param tickers: Tickers (from exchange.get_tickers()). May be cached.
+        :return: new allowlist
+        """
+        needed_pairs = [(p, '1h') for p in pairlist if p not in self._pair_cache]
+
+        since_ms = int(arrow.utcnow()
+                       .floor('day')
+                       .shift(days=-self._days - 1)
+                       .float_timestamp) * 1000
+        # Get all candles
+        candles = {}
+        if needed_pairs:
+            candles = self._exchange.refresh_latest_ohlcv(needed_pairs, since_ms=since_ms,
+                                                          cache=False)
+
+        if self._enabled:
+            for p in deepcopy(pairlist):
+                daily_candles = candles[(p, '1h')] if (p, '1h') in candles else None
+                if not self._validate_pair_loc(p, daily_candles):
+                    pairlist.remove(p)
+        return pairlist
+
+    def _validate_pair_loc(self, pair: str, daily_candles: Optional[DataFrame]) -> bool:
+        """
+        Validate trading range
+        :param pair: Pair that's currently validated
+        :param ticker: ticker dict as returned from ccxt.load_markets()
+        :return: True if the pair can stay, false if it should be removed
+        """
+        # Check symbol in cache
+        if pair in self._pair_cache:
+            return self._pair_cache[pair]
+
+        result = False
+        if daily_candles is not None and not daily_candles.empty:
+            returns = (np.log(daily_candles.close / daily_candles.close.shift(-1)))
+            returns.fillna(0, inplace=True)
+
+            volatility_series = returns.rolling(window=self._days*24).std()*np.sqrt(self._days*24)
+            volatility_avg = volatility_series.mean()
+
+            if self._min_volatility <= volatility_avg <= self._max_volatility:
+                result = True
+            else:
+                self.log_once(f"Removed {pair} from whitelist, because volatility "
+                              f"over {self._days} {plural(self._days, 'day')} "
+                              f"is: {volatility_avg:.3f} "
+                              f"which is not in the configured range of "
+                              f"{self._min_volatility}-{self._max_volatility}.",
+                              logger.info)
+                result = False
+            self._pair_cache[pair] = result
+
+        return result
\ No newline at end of file