Investors in Reddit-favorite stocks such as AMC Entertainment Holdings Inc. (AMC), BlackBerry Limited (BB), GameStop Corp. (GME) and Bed Bath & Beyond Inc. (BBBY) should focus on the upcoming inflation data that will be published this week, according to an analyst.

What Happened: Steve Massocca, managing director at Wedbush Securities, told CNBC that investors in the so-called stonks, or shares favored by the retail crowd, must focus on May’s consumer price index (CPI) that will be reported Thursday.

The CPI data could be a catalyst for the U.S. Federal Reserve to reverse its easy monetary policy. The Fed’s next monetary policy meeting is scheduled for June 15-June 16.

Noting that the market looks too expensive, Massocca said that while the retail trading mania is just one sign, a hawkish comment from the Fed could also trigger a sell-off. He believes the market is setting up for a 7% to 10% pullback at some point.

“Who knows what starts it. ... One of the candidates very likely will be some kind of reductions in monetary policy,” the analyst reportedly said.

Dan Niles, the founder of Satori Fund, was quoted as saying that he is staying away from stocks that are heavily sought by retail investors or stocks that have large short interest and are targeted by Wall Street.

Why It Matters: Ahead of a fresh trading week, it was reported on Sunday that Blackberry and AMC Entertainment were the most-mentioned stocks on the Reddit investor forum r/WallStreetBets, or WSB, over a seven-day period.

Strategists fear that the retail trading frenzy is the sign of a bubble building in the stock market. Shares of stonks have surged in recent days as retail investors pile into these stocks and attempt a new short squeeze.

AMC has skyrocketed a whopping 2,159.9% since the year began, while GameStop’s year-to-date gains stand at 1,218.3%. BlackBerry has shot up 109% in the same period.

AMC Entertainment’s valuation shot past GameStop last week amid increasing interest in the stonks.

Price Action: AMC Entertainment shares closed almost 6.7% lower in Friday’s trading at $47.91, while GameStop shares fell 3.8% to close at $248.36.

BlackBerry shares closed 12.7% lower in Friday’s trading at $13.86 and Bed Bath & Beyond shares declined 0.6% to close at $31.71.