Both the Nasdaq and the NYSE said they will cancel some of the trades executed between 2:40 and 3 PM ET on Thursday, Reuters reported, but what exactly do these broken trades mean for the rest of us?

First, it means that the machines that handle the exchanges’ transactions “went horribly wrong,” Cramer said, and “we’re a lot less sturdy than we thought a few hours ago. Second, it makes me angry. It should make you angry.”

Cramer said he’s all for electronic trading and the quick execution of trades, but not at the expense of individual investors. He does what he can to protect his viewers by endorsing diversification and dividends, and he’d like to think government can protect them, too. But they can’t.

“We’ve been sacrificed on the alter of machines … that are too fast,” Cramer said, “and too sophisticated for our own good.”

This is why Cramer emphasized again today that “stocks are not cash.” Investors should never be 100% invested, he said. They should always keep any funds they need for the short term in cash. And after a day like today, they should be reviewing their portfolios to find the names they don’t like and be ready to sell those stocks tomorrow to raise cash.

Because “we’re fragile again,” Cramer said. Maybe not as fragile as during the crash of 2008, “but we are fragile.”

“Do you have enough cash?” Cramer asked. “That should be your question.”

Call Cramer: 1-800-743-CNBC

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