The S&P 500 extended its gains on Thursday as easing oil prices and cooling Treasury yields helped offset inflation concerns, and Polymarket traders are betting the benchmark index will open higher on Friday.

The S&P 500 rose 0.17% to close at 7,445.72 on Thursday, marking its second consecutive advance after snapping a three-day losing streak earlier this week. The May 22 Polymarket contract implied a 78% probability that the index would open higher on Friday.

Why That Number Matters

Investor sentiment has improved as traders increasingly bet that a resolution to the U.S.-Iran war is more likely than not.

Oil prices continued to retreat on Thursday, with West Texas Intermediate crude falling nearly 2% to settle at $96.35 per barrel and Brent crude declining more ...