The S&P 500's most richly valued stocks fell hardest as Treasury yields hit a 19-month high

The S&P 500 fell 0.72% cap-weighted on Tuesday, with 335 of 500 constituents closing lower. Split the index by valuation, and the decline wasn't spread evenly: the 50 constituents trading at the richest price-to-sales multiples averaged a 2.0% decline, while the 50 trading at the cheapest multiples averaged a 0.23% gain — a gap of roughly 2.2 percentage points.

The backdrop: yields at a 19-month high

The 10-year Treasury yield rose to 4.79% on Tuesday, its highest level since January 14, 2025, as a renewed round of U.S. strikes on Iranian targets pushed oil prices higher and stoked inflation concerns. Reporting on the move cited markets pricing in roughly a two-in-three chance of a Federal Reserve rate hike this month, up sharply from the prior week. Higher long-term yields raise the discount rate applied to a company's future cash flows — a bigger drag on a stock priced for a decade of growth than on one already priced for very little.

What our own numbers show

Using each constituent's market cap and trailing revenue, we ranked all 500 S&P 500 names by price-to-sales and split them into ten equal groups:

Across all 500 names, the correlation between price-to-sales and Tuesday's percent change was -0.24 — weak in absolute terms, but consistent with a day where valuation, not sector, was doing a lot of the work. $CRWD (P/S of 43, the second-richest multiple in the index) fell 6.90%. $PANW (P/S 28, fifth-richest) fell 5.24%. $ANET (P/S 23, eighth) fell 3.29%. $IBKR (P/S 23, ninth) fell 7.01%. $DDOG (P/S 20, twelfth) fell 5.57%. $CDNS, priced at 15 times sales, fell 7.60% even after confirming its new chip-interconnect technology passed first-pass compliance testing — coverage of the move attributed the drop to broader concern about premium software and AI-infrastructure valuations rather than anything specific to that announcement.

Where the pattern breaks down

It isn't a clean rule, and the exceptions are worth naming. $MRNA carries one of the richest multiples in the entire index — sixth out of 500 by price-to-sales — and it rose 9.93% on Tuesday, the single biggest gain in the S&P 500. $DELL, by contrast, is priced at roughly 2 times sales, among the cheaper third of the index, and it still fell 6.80%. $AXON, which fell 8.52% (the index's worst single-day move), sits only in the top third by valuation, not the top decile. Coverage of Axon's drop pointed to yield sensitivity given its own premium multiple relative to industrial peers, plus separate concerns about margin compression from recent acquisitions — a company-specific overlay on top of the macro pressure.

So the valuation effect Tuesday was real at the index level and visible in the decile averages, but it was a tilt, not a filter: plenty of expensive stocks fell in line with the pattern, at least one of the most expensive rallied hard, and some of the day's biggest losers weren't particularly expensive at all.

What we are not claiming

We are not claiming that price-to-sales caused any individual stock's move — a -0.24 correlation across 500 names describes a tendency, not a mechanism, and plenty of names moved against it. We are not claiming today's yield level is unprecedented; 4.79% is a 19-month high, not an all-time one. We are not making any statement about whether expensive stocks are overvalued or due for a larger correction, and nothing here is investment advice. This is a description of one day's cross-section, not a forecast.