Investors already fear a looming AI bubble, but it's too early to call the peak.Shares of Bloom Energy (BE 7.77%) plunged 19.5% this week through 11:40 a.m. ET Friday, according to data provided by S&P Global Market Intelligence. There's no company-specific news, but updates from a customer are rattling investors in the hydrogen stock and compelling some to take some profits off the table. If a customer is spending more, why is Bloom Energy stock falling?Bloom Energy's hydrogen fuel cell energy servers prov ...