Stocks are mixed as midterm voting begins, with options pricing a 0.8% S&P 500 swing for Wednesday

Stocks were mixed on Tuesday as Americans voted in midterm elections, with options pricing only a modest swing for Wednesday even though control of Congress could change.

The S&P 500 was up 0.27% and the Nasdaq 100 0.60%, while the Dow was down 0.57%, as of 10:00 a.m. ET. The 10-year Treasury yield rose from 4.89% to 4.94%.

S&P 500 options imply a swing of about 0.8% either way on Wednesday, Reuters reports, citing ORATS. That is only a little above the 0.6% average of the past month.

Polls point to Democrats winning the House and leave the Senate too close to call. Prediction markets lean further: Kalshi traders gave Democrats a 77% chance of taking the Senate as of 10:17 a.m. ET, up from 74% on Monday.

Wall Street is more cautious. UBS Global Wealth Management gives a Democratic sweep 50% odds, and a Wolfe Research survey of over 100 institutional investors found no strong bet on any outcome.

JPMorgan expects the S&P 500 to lose about 0.5% on Wednesday in a Democratic sweep, and its traders see a gain of up to 1% if Republicans hold the Senate. Citigroup's strategists think a Democratic House with a Republican Senate could help stocks into year-end.

AI is the biggest exposure. Democrats could press harder on data centers, but Goldman Sachs sees a national moratorium as unlikely under any result. Analysts told Reuters they expect investigations of the tech sector more than laws that derail the buildout.

Other sectors are in play too. Analysts told CNBC a Democratic win could weigh on defense stocks and on banks, through a possible cap on credit card rates, while lifting health care.

History favors buyers. The S&P 500 rose in the year after each of the 11 midterms between 1982 and 2022, by 13.7% on average, CNBC calculates.

Not everyone expects a repeat. BTIG's Jonathan Krinsky says stocks are usually weak going into a midterm, while the index has gained double digits this year. "We think the opposite is actually more likely," he wrote of a post-election rally.

Results come in tonight, so Wednesday's session is the first full market reaction.

Sources & Further Reading

1. "Investors ready for possible shake-up in Congress as Election Day arrives." Reuters. November 3, 2026.
2. "Who will control the Senate?" Kalshi. November 3, 2026.
3. "Prediction market traders see nearly 75% chance Democrats win Senate." CNBC. November 2, 2026.
4. "Midterm elections: What a Democratic sweep means for stocks." CNBC. November 3, 2026.
5. "Stock market after midterm elections: S&P 500 history." CNBC. November 2, 2026.