Benchmark Treasury yields on Thursday briefly broke through a key line in the sand that investors say could start to present trouble for record-high U.S. equities. The 10-year note rose as high as 1.49%, before settling down to 1.46% on Thursday. In its climb higher, the benchmark maturity passed the S&P 500's /zigman2/quotes/210599714/realtime SPX +0.77% average dividend yield of 1.48%. That could raise the relative attractiveness of U.S. government bonds to the expense of high dividend-paying sectors like utilities. If long-term bond yields persist above the dividend rates paid out by major U.S. corporations, analysts have said it could add to concerns around elevated valuations in the stock market. The S&P 500 is down 0.9%, leaving it on pace for a 0.4% loss for the week.