"First, keep an eye on China," Cramer counseled. There are a growing number of reports which suggest China is facing a credit bubble that's 'unlike anything in modern history.'
"What the heck is really going on in China? I have no idea," Cramer said. "It could be an incredible stress to the banking system over there. Stress in any banking system is going to reverberate all over the place. We know that from the big declines we had here when banks in Cyprus went bust. Banks in China are huge. They could take us down two-three percent in a heartbeat."
Also Cramer said trouble may bubble up in Brazil.
Unrest has spread rapidly in Brazil since June 13th, the day police cracked down on a small demonstration over rising bus and subway fares in Sao Paulo. The magnitude of the resulting violence has shocked a country that until recently was considered a successful emerging-market power on the rise.
"A million people took to the streets there the other day to protest the government," Cramer said. Could we be seeing a bout of socialism coming on in this former engine of world growth, one that so many thought would be strong going into the 2016 Olympics? That's unsettling."
India could also drag down markets.
Asia's third largest economy has been disappointing over the past year, with growth remaining sluggish in the January to March period at 4.8 percent from 4.7 percent in the previous quarter. Meanwhile, the nation is also facing serious inflation. "Slowing growth and increasing inflation What could be worse? Nothing," Cramer said.
Cramer is also worried about Russia.
"The oil wealth seems to be increasingly tapped out. That market's hitting lows that we haven't seen in ages."
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All told Cramer sees cause for concern. Any one of these landmines could explode with little notice. And should that happen, market pros will go scrambling for cover.
Therefore Cramer says although the sell-off may entice you to buy a favorite stock; exercise some restraint. "Don't reach and don't get too aggressive. Instead wait. That's what I am advising now. "
