"Machines are taking control of investing—not just the humdrum buying and selling of securities, but also the commanding heights of monitoring the economy and allocating capital."
Total US equity market cap is around 30 trillion. Total money in ETFs is 4.5 trillion. So at the very least machines are investing over 10% of capital. Probably more like 20-30%
Of course this only US and only equities, but it's still well above 1%.
I think machines investing is less than 1%;