New Delhi, Aug. 6 -- As stocks mark a 100 percentage-point gain from the start of the artificial-intelligence boom and hit all-time record highs, it might seem churlish to sound the alarm about dangers lurking beneath the surface.

But the recent turmoil tied to the Situational Awareness hedge fund, the worrying upheaval in tech-focused markets in Asia, and the Federal Reserve's new strategy of policy omerta has some investors worried that markets might be missing the impact of smaller events as they calibrate the odds of a revival of 2008 risks in global markets.

" 'Small vol' events are going to affect markets with an increased frequency," wrote Deutsche Bank analysts Luke Templeman and Galina Pozdnyakova in a recent client note. "The ...