New Delhi, May 24 -- Charles Schwab spent a good chunk of its six-hour-long investor day on May 14 explaining to analysts and shareholders how the company is using artificial intelligence to boost its business. Investors, however, are far more focused on whether AI poses a threat to the substantial profits Schwab derives from so-called sweep cash, the money that clients hold in brokerage accounts that earn almost no interest. AI could change that equation by powering tools that allow investors to automatically move idle cash from their brokerage account to money-market funds or other higher-yielding accounts that are far less profitable for Schwab, as well as other brokerages that derive profits from customers' cash.

The AI threat more b...