Blackstone's Byron Wien believes the market decline isn't completely over.

"I don't think the overall market has cleansed itself enough to represent a broad buying opportunity. I think we have more work to do," he said Friday on CNBC's "Squawk Alley." "I think we will end the year higher than we started, but I think we may not be done with this correction yet."

Wien predicted on Jan. 2 that the market would have a 10 percent correction this year as one of his "Ten Surprises for 2018." The S&P 500 fell officially into correction territory Thursday, down more than 10 percent from its record reached in January.

The investor thinks the market volatility is not a sign of an imminent recession. He cited strong economic numbers such as leading indicators and unemployment figures.

"We've been waiting for a 10 percent correction for over a year now. And now we're having it, so it's really not a surprise," he said. "It's a healthy cleansing. Is it the beginning of a bear market? I think not. The economy is revving along at a frequent pace. It looks like growth this year is going to be pretty close to 3 percent."

The Wall Street veteran has been publishing his list of surprises since 1986. Wien defines a "surprise" as something the average investor would assign only a 33 percent chance of taking place, but which he thinks has a more than 50 percent chance of happening.

Wien is vice chairman of Blackstone's Private Wealth Solutions group. Previously, he was the chief U.S. investment strategist at Morgan Stanley.