The bank slashed its price target for the iPhone maker for the second time in two months on Monday.
In a note titled "It Might Rain on Buyback Exuberance," Barclays put a price target of $157 on Apple, down from $168, representing a nearly 5 percent downside from Monday's close.
The problem it sees is that many people are holding the stock because of high expectations around capital return. Apple said that it will bring back its offshore cash of around $258 billion to the U.S. following President Donald Trump's plan to reduce the tax rate on money repatriated to America.
Many analysts expect Apple to announce a significant share buyback program and dividend increase. Barclays said that many investors are holding Apple stock in hope of a payout, but the risk is that Apple could give back less than expected, because more money needs to go to acquisitions due to the possibility of weaker iPhone sales.
"Our concern is that a weaker iPhone franchise could require the company to allocate more cash to M&A," Barclays said in the note.
"In contrast, we think many holders are in the stock for capital returns being the main beneficiary of excess cash. As a result, there could be a sell on the news event around the... earnings call if capital returns are only in line with expectations, set against a backdrop of softening earnings power."