The end of the Federal Reserve's $600 billion bond buyback program will send stock prices falling this summer, although they'll likely rebound later in the year, says Byron Wien, vice chairman of Blackstone Advisory Services.

The $600 billion bond buyback, known as quantitative easing, is the Fed's second such program that forms part of a larger effort to spur economic growth by pumping money into banks.

This second round, nicknamed QE2, has been good for the stock market, but it's due to end in June and similar measures are unlikely to follow.

NYSE traders (Getty photo)

"It's hard for me to assess how much of the big move in stocks since the end of last summer was attributable to the fact that money was so plentiful and not much of it went into the real economy," Wien tells CNBC.

"An enormous amount went into financial assets. In June that money is going to be choked off, QE2 is going to be over, and I don't think there is going to be a QE3 and so therefore I think the market could be vulnerable."

Others point out that economic recovery is strong enough to keep stocks from tanking once the Fed's money evaporates in June.

"The economic recovery is much stronger than most give it credit for, and so much of the talk about the end of QE2 is factored in already," Ryan Detrick, senior technical strategist at Schaeffer's Investment Research, tells CNNMoney.

"[The Fed] has stated that they are going to do all they can to keep the economy moving," Detrick adds.

"We still expect a strong second half of the year."