(Bloomberg) -- One of the stock market's favorite momentum plays from earlier this year is re-emerging as rising confidence in artificial intelligence spending sends the shares of optical component makers soaring again. The leader, Applied Opto, has soared 76% in just nine sessions, while Coherent has gained 48% over that stretch. Applied Opto, Coherent, Fabrinet and Corning all gained in premarket trading Wednesday after Lumentum's fourth-quarter earnings and first-quarter outlook both topped analyst expectations. Right around that time, however, investors started turning skeptical about AI spending. At this point, the outlook for capex from the major hyperscalers is more important to these stocks than the companies' individual results.