Moving Average Entries with Trailing Stop Exit Backtests
Summary
This Backtrader example enters a long position when a short-period simple moving average crosses above a longer-period average. Once a position exists, it submits a sell stop order, configurable as a trailing stop or trailing stop-limit. The trailing distance can be specified as a fixed amount or a percentage, and the stop-limit variant uses an offset from the current close. The script prints the close, created stop price, and a calculated reference level as bars progress. It also supports configurable data dates, broker and position-sizer settings, strategy parameters, and optional plotting. The document is an implementation example rather than a performance study: it provides no reported backtest results, transaction-cost analysis, or comparison against alternatives. Its entry rule is long-only, and the sample does not describe position exits beyond the trailing order or discuss how parameter choices should be validated.
Key ideas
- A bullish crossover of two configurable simple moving averages opens a long position.
- After entry, the strategy places a trailing sell stop or trailing stop-limit order.
- The trailing distance can be set as a fixed price amount or a percentage.
- The example reports stop-related values during execution but gives no performance evidence.
- Broker, sizing, date range, strategy, and plotting options can be configured when running the sample.
Tags
Full text
# trail.py
```py
#!/usr/bin/env python
# -*- coding: utf-8; py-indent-offset:4 -*-
###############################################################################
#
# Copyright (C) 2015-2023 Daniel Rodriguez
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
###############################################################################
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import argparse
import datetime
import backtrader as bt
class St(bt.Strategy):
params = dict(
ma=bt.ind.SMA,
p1=10,
p2=30,
stoptype=bt.Order.StopTrail,
trailamount=0.0,
trailpercent=0.0,
limitoffset=0.0,
)
def __init__(self):
ma1, ma2 = self.p.ma(period=self.p.p1), self.p.ma(period=self.p.p2)
self.crup = bt.ind.CrossUp(ma1, ma2)
self.order = None
def next(self):
if not self.position:
if self.crup:
o = self.buy()
self.order = None
print('*' * 50)
elif self.order is None:
if self.p.stoptype == bt.Order.StopTrailLimit:
price = self.data.close[0]
plimit = self.data.close[0] + self.p.limitoffset
else:
price = None
plimit = None
self.order = self.sell(exectype=self.p.stoptype,
price=price,
plimit=plimit,
trailamount=self.p.trailamount,
trailpercent=self.p.trailpercent)
if self.p.trailamount:
tcheck = self.data.close - self.p.trailamount
else:
tcheck = self.data.close * (1.0 - self.p.trailpercent)
print(','.join(
map(str, [self.datetime.date(), self.data.close[0],
self.order.created.price, tcheck])
)
)
print('-' * 10)
else:
if self.p.trailamount:
tcheck = self.data.close - self.p.trailamount
else:
tcheck = self.data.close * (1.0 - self.p.trailpercent)
print(','.join(
map(str, [self.datetime.date(), self.data.close[0],
self.order.created.price, tcheck])
)
)
def runstrat(args=None):
args = parse_args(args)
cerebro = bt.Cerebro()
# Data feed kwargs
kwargs = dict()
# Parse from/to-date
dtfmt, tmfmt = '%Y-%m-%d', 'T%H:%M:%S'
for a, d in ((getattr(args, x), x) for x in ['fromdate', 'todate']):
if a:
strpfmt = dtfmt + tmfmt * ('T' in a)
kwargs[d] = datetime.datetime.strptime(a, strpfmt)
# Data feed
data0 = bt.feeds.BacktraderCSVData(dataname=args.data0, **kwargs)
cerebro.adddata(data0)
# Broker
cerebro.broker = bt.brokers.BackBroker(**eval('dict(' + args.broker + ')'))
# Sizer
cerebro.addsizer(bt.sizers.FixedSize, **eval('dict(' + args.sizer + ')'))
# Strategy
cerebro.addstrategy(St, **eval('dict(' + args.strat + ')'))
# Execute
cerebro.run(**eval('dict(' + args.cerebro + ')'))
if args.plot: # Plot if requested to
cerebro.plot(**eval('dict(' + args.plot + ')'))
def parse_args(pargs=None):
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter,
description=(
'StopTrail Sample'
)
)
parser.add_argument('--data0', default='../../datas/2005-2006-day-001.txt',
required=False, help='Data to read in')
# Defaults for dates
parser.add_argument('--fromdate', required=False, default='',
help='Date[time] in YYYY-MM-DD[THH:MM:SS] format')
parser.add_argument('--todate', required=False, default='',
help='Date[time] in YYYY-MM-DD[THH:MM:SS] format')
parser.add_argument('--cerebro', required=False, default='',
metavar='kwargs', help='kwargs in key=value format')
parser.add_argument('--broker', required=False, default='',
metavar='kwargs', help='kwargs in key=value format')
parser.add_argument('--sizer', required=False, default='',
metavar='kwargs', help='kwargs in key=value format')
parser.add_argument('--strat', required=False, default='',
metavar='kwargs', help='kwargs in key=value format')
parser.add_argument('--plot', required=False, default='',
nargs='?', const='{}',
metavar='kwargs', help='kwargs in key=value format')
return parser.parse_args(pargs)
if __name__ == '__main__':
runstrat()
```Shown in full with attribution under the source's licence. Licence: GPL-3.0
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.