Utilities Stocks Lead the S&P 500 in the AI Power Trade

The S&P 500 set a record close on Tuesday, October 6, and for the first time in this cycle the sector that led had a rally easier to explain with a power purchase agreement than with a chip. Utilities advanced 2.98%, the best of eleven sectors, after Alphabet’s Google signed a long-term nuclear-power deal with Constellation Energy and the Energy Department offered up to $4.2 billion in conditional financing to Vistra. The market is now pricing AI capex as a bet on electricity itself, not just on the hardware that burns it.

Breadth behind the move was healthier than the level alone suggests, with ten of eleven S&P 500 sectors finishing higher and Health Care the only decliner at negative 0.17%, and NYSE advancers outnumbering decliners by roughly 1.93 to 1. Yet the rally did not reach small caps: the Russell 2000 fell 0.72% even as the index set its record. That split, strong participation among large caps and none among small, is the signal to watch, and it points straight back to the long end of the curve.

Related reading: Utilities lead rotation as the S&P caps at 7,670 into quarter-end.

Two headlines did the heavy lifting for the AI power complex. Constellation jumped about 12% after Google agreed to purchase nuclear output, including roughly 890 megawatts of new capacity across 11 reactors plus a separate firm-output deal, a structure WSI.news tallies near 3,590 MW total. Vistra rose about 11% after the Department of Energy announced conditional financing of up to $4.2 billion. Both moves read as the market paying for the next leg of the AI buildout, the megawatts that feed the data centers, and etf.net and WSI.news both noted the lift to XLU ran nearly 1.8 percentage points clear of second-place Consumer Discretionary, a gap a 4 basis point yield decline on its own does not explain.

Elsewhere in the semiconductor complex, the same read showed up. AI accelerators, networking and power names rose, with Broadcom up 3.67%, Marvell up 5.8% and AMD up 2.8%, while memory and chip equipment fell: Micron down 1.73%, SK hynix American depositary receipts down 6.39%, Lam Research down 3.44% and ASML down 1.39%. Accelerators and the electricity they need moved up together; the components that serve a slower part of the stack lagged. The market is pricing each leg of the AI supply chain on its own monetization, not treating AI as a single monolith.

For the broader framework, see our crude oil coverage.

Related reading: S&P 500 record 7,818.95 on a 5.3% long yield: big caps climb while small caps and semis lag.

Macro is the binding constraint on this trade. Per etf.net and Kalkine, the 10-year Treasury yielded 5.27% on Tuesday, easing 4 basis points, with the 30-year at 5.64%, the highest long-term yields in roughly 24 years. A single 4 basis point pullback is not enough to re-rate small caps, highly indebted balance sheets or long-duration assets, which is why the Russell moved lower even as the index hit records. September payrolls rose just 29,000, a softening hiring backdrop the market is reading as a mild drag rather than recession fuel, but it blunts the earnings-growth case that would normally justify cyclical leadership.

Concede the contrarian case more weight than a record tape usually gets. This is a rate-sensitive trade: utilities and real estate rallied precisely because long yields eased a touch, and Real Estate followed at plus 1.06%. If the 10-year turns back up and through 5.4%, near the October 5 close that was already the highest in 24 years, the utility and REIT leadership could unwind quickly and drag the index with it.

Related reading: Bloom Energy Tops $1B as AI Data Centers Drive Rotation.

Watch the September CPI report on October 14 as the trigger. A hot print would reinflate inflation expectations and pressure long yields again, while a soft one could finally unlock the small-cap catch-up the breadth data have been teasing. Mega-cap bank earnings open on October 13, where net interest income and credit costs meet a 5.3% ten-year, setting the tone before CPI lands.

For now the index’s near-term path is dominated by the long end of the Treasury curve, not by equity fundamentals. At a record high, that is the point worth remembering: the same 5%-plus yield regime that powered Tuesday’s utility bid is the risk that would take it back. The next CPI print decides which way the rotation breaks.

Related reading: Google Constellation Deal Adds 890 MW Nuclear Power to PJM.

This content is for informational purposes only and does not constitute financial advice. Past performance is not indicative of future results. Consult a qualified financial advisor before making investment decisions.