graphics – How can I add my financial indicator to be plotted in a TradingChart?

Since this question was not answered, I would like to ask again with some additional information. I have

ohlcv = FinancialData["SPY","OHLCV", {DatePlus[Today, -300], Yesterday}];
chart1 = TradingChart[ohlcv, {"Volume", "BollingerBands"}];

I have created the following indicator:

myind = Accumulate /@ SplitBy[Differences[
      Log[QuantityMagnitude[ohlcv["Values"][[All, 4]]]]], Sign] //Flatten;
myindts = TimeSeries[myind, {Most[ohlcv["Dates"]]}];
chart2 = DateListPlot[myindts];

I want to plot my indicator below the main trading chart. How can I achieve it? Any help would be appreciated.