A 21% Surge Shows Allure of VIX Products as SEC Issues New Fine

On the very day U.S. regulators announced the latest fine related to complex volatility products, market gyrations showed just why these controversial strategies are in hot demand on Wall Street.

As stocks sank Monday and the Cboe Volatility Index spiked, the ProShares Ultra VIX Short-Term Futures ETF (ticker UVXY) jumped 21% -- trouncing almost every U.S. exchange-traded fund out there.

It underscores the appeal of these complicated trading vehicles, which have been embraced by everyone from old-school investors seeking protection to daytraders wielding rocketship emojis.

With 1.5 times leverage, products like UVXY are designed to post outsized gains when ...