"I didn't realize China would have such an effect on the U.S. and Europe," he wrote. "The [Shanghai Stock Exchange Composite Index] is up over 32% this year. The [S&P 500] is barely up over 2%. But c'est la vie, apparently."
Although there has not been a perfect correlation between U.S. stocks and booming Chinese equities, any worries about the future of those markets would cause some doubts stateside, according to Jim Meyer, CEO of Tower Bridge Advisors.
"The Chinese market has been a source of strength," he explained, so any decline could rattle equities traders.
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Any global weakness from the Chinese regulatory changes should be temporary, however, said Adrian Day of Adrian Day Asset Management.
Such a move was not unexpected, he said, given the fact that Chinese equities "have sort of gone crazy" with massive gains in recent months. And while the new rules may tamp down on those prices, the easily-spooked global markets should move along to the next focal point.
"By next week the rest of the world will have forgotten about it," Day said.
—Reuters and CNBC's Evelyn Cheng contributed to this report.