The very leftmost column of the table has the heading 'S&P 500 (includes dividends)', so I assume that's the meaning of 'stocks' in the other columns. If not, that would be very misleading.
So at the £5ish/trade of my current broker, that's a cool £912500/year on just commission.
For some reason the massively reduced ease of entry to a trading strategy like this is never considered when lauding its historical performance.
Modern S&P500 funds like SPY or VOO rebalance quarterly FYI