The Stock Market Rally Faces a Stark Reality. Things Could Get Tricky.

The roaring U. S. stock market, powered by bets on tech and artificial intelligence that has lifted indexes to a series of record highs over the past six weeks, may have finally found a challenge it can’t easily overcome.

Benchmark 10-year Treasury note yields jumped more than five basis points in overnight trading, pegging the paper at 4. 535%, the highest in nearly a year.