If your first datas is data0, then when building your second and other datas you need to insert:

data1.plotinfo.plotmaster = data0

So for example, if loading three datas from a dataframe, it would look like this:

# Add Nasdaq qqq data line. data0 = bt.feeds.PandasData( dataname=pd.read_hdf("store.h5", "qqq").loc[date_start:date_end, :], name="qqq", plot=True, ) cerebro.adddata(data0) # Add S&P500 spy data line. data1 = bt.feeds.PandasData( dataname=pd.read_hdf("store.h5", "spy").loc[date_start:date_end, :], name="spy", plot=True, ) data1.plotinfo.plotmaster = data0 cerebro.adddata(data1) # Add S&P short SH data line. data2 = bt.feeds.PandasData( dataname=(pd.read_hdf("store.h5", "sh").loc[date_start:date_end, :]), name="sh", plot=True, ) data2.plotinfo.plotmaster = data0 cerebro.adddata(data2)