Interactive broker- a wrong historical close price

PavelAn

Hello,
I've imported a historical close prices for FB but they are wrong!
I've got:

Server Version: 76
TWS Time at connection:20181006 22:40:53 MSK
1,2018-09-18T00:00:00,159.51
2,2018-09-19T00:00:00,159.90
3,2018-09-20T00:00:00,163.37

But they must be:
1,2018-09-18T00:00:00,160.30
2,2018-09-19T00:00:00,163.06
3,2018-09-20T00:00:00,166.02

https://finance.yahoo.com/quote/FB/history?period1=1537218000&period2=1537390800&interval=1d&filter=history&frequency=1d
My code:

from __future__ import (absolute_import, division, print_function,
                        unicode_literals)

import datetime
import backtrader as bt

class St(bt.Strategy):
    def logdata(self):
        txt = []
        txt.append('{}'.format(len(self)))
           
        txt.append('{}'.format(
            self.data.datetime.datetime(0).isoformat())
        )
        #txt.append('{:.2f}'.format(self.data.open[0]))
        #txt.append('{:.2f}'.format(self.data.high[0]))
        #txt.append('{:.2f}'.format(self.data.low[0]))
        txt.append('{:.2f}'.format(self.data.close[0]))
        #txt.append('{:.2f}'.format(self.data.volume[0]))
        print(','.join(txt))

    def next(self):
        self.logdata()

def run(args=None):
    cerebro = bt.Cerebro(stdstats=False)
    
    store = bt.stores.IBStore(port=7497)
    dtformat = '%Y-%m-%d'
    data = store.getdata(dataname='FB', historical=True, fromdate = datetime.datetime.strptime('2018-09-17', dtformat), todate = datetime.datetime.strptime('2018-09-20', dtformat), timeframe=bt.TimeFrame.Days, compression=1 ) 
	
    cerebro.adddata(data)
    cerebro.addstrategy(St)

    cerebro.run()

	
	
if __name__ == '__main__':
    run()

Where is my mistake? Please, help.

backtrader

I don't think you are making anything wrong.

Since you use port 7497 (which is usually for the Paper Trading Acccount), it's where the different may be. Try the regular account (you can download data and forbid any trading via the API in the settings)

z_kvn

@pavelan Just a wild guess, please don't take my words without testing. Backtrader is using "rightedge=True" by default, meaning at timestamp "2018-09-18T00:00:00" you are seeing the information for the period "2018-09-17T00:00:01" to "2018-09-17T23:59:59" roughly. In other words, "2018-09-18T00:00:00" marks the end of "2018-09-17".

While on most other places like Bloomberg or even InteractiveBroker, a timestamp "2018-09-18" marks the beginning of a bar, meaning that the OHLC for the bar associated with timestamp "2018-09-18T00:00:00" is for what has happened during the day time of "2018-09-18".

backtrader

@pavelan said in Interactive broker- a wrong historical close price:

data = store.getdata(dataname='FB', historical=True, fromdate = datetime.datetime.strptime('2018-09-17', dtformat), todate = datetime.datetime.strptime('2018-09-20', dtformat), timeframe=bt.TimeFrame.Days, compression=1 ) 

cerebro.adddata(data)
cerebro.addstrategy(St)

There is no resampling, historical=True and timeframe=bt.TimeFrame.Days. The user should be getting the bars which are delivered (unless, it happens sometimes, the user has posted output which doesn't correspond to the sample code)