Boockvar: Key takeaway from China-based selloff

China's stock market plunge signals a slowdown in the U.S. economy, Lindsey Group chief market analyst Peter Boockvar said Tuesday.

"Yesterday, the most important thing was the high-valued stocks that were immune to this in 2015 finally succumbed to the selling that we saw underneath the market," Boockvar told CNBC's "Worldwide Exchange."

U.S. equities fell sharply Monday — the first trading day of 2016 — with the Dow Jones industrial average and the S&P 500 each plunging about 1.5 percent. The Nasdaq composite tumbled 2 percent.

The selloff was triggered by a 6.86 percent fall in China's Shanghai composite on Monday, which set off the newly placed circuit breakers, effectively halting trading.

"China doesn't like anything disorderly, and they got a taste of it on the first day of the year, and they tried to calm things down," Boockvar said.

"But China is only part of the picture. China's economy has been slowing for years. China's stock market obviously had its craziness last year, but the underlying context is the Chinese economy has been slowing for years, but it's a wake-up call to the markets that the U.S. economy is slowing down; the global economy is slowing down, and central bankers are losing their effectiveness in propping things up."

U.S. manufacturing contracted in December, the Institute for Supply Management said Monday, while weak Chinese manufacturing data weighed on Asian equities.

Phil Orlando of Federated Investors said Chinese growth fears may be overblown.

"Investors came back from Christmas and New Year's break having a little bit of a flashback to China in the summer," the firm's chief equity strategist told CNBC's "Squawk Box" on Tuesday.

"Everyone's ignoring the services portion of the economy, which is now more than half of the economy; they're focused on manufacturing, which has been decelerating for five years, and it's going to keep decelerating for the next five years; there's no new news there."

He also said many of these fears will be subdued by the end of the week, as he expects strong service sector data on Wednesday and a solid December jobs report on Friday. "By the end of Friday, investors are going to say the U.S. isn't so bad."