Stocks looked set to struggle for direction on Tuesday as investors tried to make sense of yet another selloff tied to worries about rapid advancements in artificial intelligence. The indexes plunged on Monday, with the Dow shedding more than 800 points after a viral blog post by Citrini Research described a hypothetical scenario where AI drives the unemployment rate above 10% by 2028. Shares in food delivery apps, credit-card providers, and alternative asset managers tumbled.