This week's crazy market swings are largely due to a band of uninformed investors who got caught speculating, CNBC's Jim Cramer said Thursday.

"A group of complete morons" who traded little-known, leveraged products that bet on volatility is "blowing up" everything, Cramer said on "Squawk on the Street."

Cramer has been particularly critical of the VelocityShares Daily Inverse VIX Short-Term exchange-traded note, which is traded under the symbol XIV, and those who put money into it.

The XIV is supposed to give the opposite return of the VIX, Cboe's volatility index, which is often referred to as the market's fear gauge.

Amid the market tumult, Credit Suisse said Tuesday it will end trading for its XIV later this month after the note lost most of its value and sent investors scrambling for cover.

"What bothers me is the people who have never looked at a stock and don't know how to analyze it [are] out in full force today," said Cramer, host of "Mad Money."

"They've never been better about not knowing anything about the stocks," he said. "They got it all figured out," he added, sarcastically.