The last few minutes of the trading day

I found something on some of my charting. The EFI indicator does something in the last two minutes of the day if there is going to be a big jump gap up or gap up the next trading day. The indicator suddenly jumps up or down at the last minute.
Kind of a problem, because its a last minute thing. Yesterday I was watching it 5 minutes before close, saw no action, so I closed shop for the day. Today I went back and took a look and dammit, there it was, a big plunge down the last 2 minutes of trading fortelling a gap down for the morning where I could have made a lot of money if I had bought puts on the QQQ 2 min before close and when the QQQ opened down in the morning I would have made a nice bit of money.

Look at the above chart and look at the second indicator, the EFI. See the redline suddenly dropped hard right before yesterdays close? Now look at the morning drop.
Yes. This is where some money can be made. So I am going to watch this today and over the next few days to allay my fears that this retroactively shows up after market close. Which it shouldnt: because I use realtime data.
As for trading today? What a snooze. Very little volitility and it was like pulling teeth. I will see if there is anything today toward the end of day.

Tradinginsider