As America's tech titans report earnings this week, one question looms large: is the artificial intelligence boom that has inflated valuations headed for the next big bubble? Microsoft, Alphabet, Amazon and Meta are poised to report that revenue rose at a brisk pace in the July-September quarter, according to LSEG data. The companies themselves are likely to say they will continue to pour billions into AI because it holds promise in the long term. But business leaders including OpenAI CEO Sam