UVXY is about as volatile an ETF as you can find. It does not always follow mkt direction, and often defies logic as to its path.
I have traded it very infrequently in the past few years, and about 75% of the time I lose money. Even when the SP500 or Nasdaq
drops it doesn't always follow that move. It can have big rewards on sudden downturns, but with the relentless bid under the market, it usually grinds lower as investors buy any dips they can find.
So if you are bearish on the market, I would recommend buying
an inverse ETF like SDS or QID (you can also find 1x versions of these). The inverse ETF will definitely follow the indexes.
The UVXY will usually leave you crying. Unfortunately,
I am the first to start watching it when we get a gap down in the market. But the gains you get fade so quickly, unless you have
tight trailing stops, it's hard to cash out with a profit.