Stock Market Today: Dow, S&P 500 and Nasdaq turn lower as upbeat data push up Treasury yields; oil prices rise

Wall Street opened the fourth quarter higher Thursday, then reversed lower before midday as stronger-than-expected economic data pushed Treasury yields up and oil prices rose.

The Dow Jones Industrial Average, S&P 500 and Nasdaq Composite all started Thursday with gains at the opening bell. Investors were weighing Micron's blowout earnings report, which supplied the early bid. The rally did not hold. By ahead of midday, all three major benchmarks had flipped negative.

The catalyst for the reversal was the data. Upbeat economic readings lifted Treasury yields, and crude oil climbed alongside them. Rising yields and rising oil are a combination that tends to pressure equity valuations, since higher yields raise the discount rate on future earnings while firmer oil can feed inflation concerns. That is interpretation, not reported fact, but it fits the tape: strong data worked as a headwind for stocks rather than a tailwind.

The sequence is the story. A single-name earnings beat from Micron was enough to lift indexes at the open but not enough to offset a macro repricing in the bond market. The move shows that rates, not earnings enthusiasm, set the tone as Q4 began.