You will end up holding overnight to keep from taking a loss.
Then the RIFIN will go positive, and instead of the 2.2X performance up FAZ usually sees and is seeing today, it's going to give you 3.5X performance down as it did both Monday and Wednesday. (Tuesday ended at 1.4X up)
You will eventually sell in the red with a 3% slip on the RIFIN, and then start all over again with this guessing game.
You can't daytrade an ETF that gives you 1.5X up and 3.5X down, and holding overnight is the kiss of an automatic 1% slip on the RIFIN.