S&P 500 is making new ATHs, but volume is noticeably lower compared to the Jan 29 selloff.

The S&P 500 is pushing to new all-time highs, but daily volume (looking at SPY as a proxy) appears notably lower compared to the Jan 29 selloff.

During that decline, volume expanded significantly, suggesting broad participation and urgency on the downside. In contrast, the current move higher looks more like a steady grind with lighter participation.

One possible explanation is the growing role of passive inflows and corporate buybacks, which can support prices without the same volume profile. That said, historically stronger breakouts tend to be accompanied by expanding volume and broader market participation.

From a technical perspective, this kind of divergence doesn’t necessarily signal an immediate reversal, but it does raise questions about the strength and sustainability of the move if participation doesn’t improve.