A sign to an Nvidia office building is shown in Santa Clara, Calif., on Aug. 7, 2024. (Jeff Chiu / Associated Press) The artificial intelligence boom seems unstoppable, but a growing number of investors and other observers worry it could be a bubble about to burst. After skyrocketing more than 50% from April lows, the tech-heavy Nasdaq composite experienced a decline of close to 5% this month. Investors are concerned it could take longer than expected to see big profits from the trillions of dollars they ...