Another flashing red signal was the Baltic Freight index. Cramer uses this as a key barometer for China, as it is the measure of raw materials shipped in bulk, mostly to China. It has been down for four straight days, which is bad news for the bulls.
The third was the dollar, which became stronger. Companies have suggested analysts to raise numbers for their international businesses, but that could quickly vanish if the dollar continues to rise. Many industrial stocks soar on a weaker dollar.
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The fourth was interest rates, an area where many banks cash in by charging more on loans, which suddenly stalled out. That's why the bank stocks fell, Cramer said.
He also pointed to health care, airlines and technology stocks getting crushed as a driver to the sell-off.
Finally, there was the election, with Ted Cruzand John Kasich announcing their departures from the presidential race.
"While it shouldn't be a shocker that Donald Trump is going to be the Republican nominee for president, I think it's dawning on people that he is a rock-hard protectionist," Cramer said.
Many international companies now recognize that business will be tougher if trade wars are launched by Trump. At the same time, Cramer suspects Bernie Sanders' decision to stay in the race is preventing Hillary Clinton from taking a pro-business stance, at least until the convention.
So, on the surface, neither party seems hospitable to business. And it seems the surface is all that matters to investors.
"If you believe all the major themes that propelled us up from the February lows are still intact and this is simply a minor chord reversal, then this is not the time to panic," Cramer said.
If oil goes back up, Cramer anticipates stocks could come bouncing back. Additionally, he suspects that many investors were too bullish and are simply taking a profit. He considers that to be a rational sell-off that creates opportunity.