Actually, there is no mistake. The quote I gave you was on Friday April 17 at 12:30PM so it did not show the entire day session. Below is the chart of SPY vs ES.D. The blue line on the very bottom is the 20 period moving average of the ratio of Price*Volume*Bigpointvalue of the 2 instruments. The data showed about a 3.75x higher total dollar amount traded in the S&P500 futures ES compared to the SPY etf. Not quite the value of 5x I quoted earlier, but 5x is pretty close to the 4.90 daily value (red line, bottom panel) reached on Friday.