Palantir Slump Signals Valuation Risk Creeping Into S&P 500

Palantir's stock is unwinding its strong postearnings rally from August, with rising bond yields and competitive pressure from Google cited as key drags. The reversal highlights how quickly sentiment can turn on the S&P 500's most richly valued growth names once yields move against them.

This isn't isolated. Broadcom's post-earnings drop despite beating estimates suggests the market is scrutinizing valuation multiples across the AI complex, not just headline results. When yields rise, as New York Fed's Williams' commentary suggests they might continue to, high-multiple stocks tend to underperform first.

For S&P 500 traders, the pattern points to rotation risk within the index rather than a broad-based selloff, with the priciest AI and data-analytics names most exposed to further multiple compression.