What happened in the US midterms?
Democrats won control of both chambers of Congress in Tuesday's midterm elections, according to projections from the Associated Press and the BBC's results tracker. The BBC put Democrats on 53 Senate seats, a gain of seven, with 29 of 35 contested races counted.
The party flipped at least six Senate seats. Troy Jackson unseated five-term Republican Susan Collins in Maine, Adam Hamilton won Kansas, and Josh Turek took Iowa. Sherrod Brown won Ohio, and Democrats also picked up seats in North Carolina and South Carolina.
In Texas, Gina Hinojosa defeated Republican governor Greg Abbott, and James Talarico beat Ken Paxton in the Senate race. Wired described the night as one that exceeded the party's highest expectations. Democrats also won governorships in Iowa, Ohio and Georgia.
The BBC projected at least 239 House seats for Democrats and at least 161 for Republicans. Control of Congress matters to the technology industry because the chamber writes tax law, sets appropriations and runs oversight. It does not set chip export controls or tariffs, which remain with the executive branch.
The campaign was dominated by living costs. Petrol averaged $4.17 a gallon on the Sunday before the vote, nearly 40% higher than a year earlier, according to AAA figures cited by CNBC. Opposition to data centres also featured in some races, including Ohio's Senate contest, Euronews reported.
Democrats also recovered ground with Hispanic voters, who had helped secure Trump's 2024 victory and swung back toward the party, the BBC reported. Black Democrats in southern states turned out in record numbers. Republican hopes that redistricting would add five Texas seats appear to have backfired.
Donald Trump told the Wall Street Journal he thought his administration would work with the Democrats. He had earlier said he would become "Mr Veto" if the party won Congress, Euronews reported. A veto strategy would cap what Democrats can legislate, even with both chambers.
How did AI stocks react to the Democratic sweep?
Wall Street closed before the scale of the Democratic win became clear. On Tuesday the S&P 500 rose 0.37%, the Nasdaq Composite gained 0.83% and the Dow fell 0.38%, the Guardian reported.
That rally ended a short selloff rather than greeting the result. The Nasdaq had closed Monday 10% below its record set on 6 October, and October was its worst month since March 2025. Nvidia rose 2.3% after four down sessions, while AMD, Broadcom and Micron also gained.
Futures moved the other way overnight. S&P 500 futures were down 0.34%, Nasdaq-100 futures 0.48% and Dow futures 72 points by early Wednesday, CNBC reported. The selling was sharper in Asia, where Japan's Nikkei 225 fell 4.45% to its lowest level since May.
Asia trades first, so Wednesday's session was the earliest read on how investors interpreted the result. Technology shares led losses across the region, Euronews reported, as investors weighed tighter AI rules and political gridlock in Washington.
Japanese technology names led the decline. SoftBank Group dropped more than 8%, chip equipment maker Disco fell 10.19%, Advantest shed more than 8% and Tokyo Electron lost 7.04%, CNBC reported. In South Korea, SK Hynix fell 5.08% and Samsung Electronics 3.87%.
Investors moved into government bonds. The 10-year Treasury yield slipped about five basis points to 4.902%, while the dollar weakened to 157.63 yen against the Japanese currency, CNBC and Euronews reported. Brent crude traded near $103 a barrel, down from $117 at the end of October, the Guardian reported.
Not every position moved in the same direction. Solar shares rose in overnight trading on hopes that a Democratic Congress would reverse policies hostile to renewables, CNBC reported. Trump Media & Technology fell more than 7%.
Why does Texas matter so much to the AI buildout?
Texas accounts for roughly 27% of US data centre capacity measured in gigawatts, according to a Wells Fargo estimate cited by CNBC. That makes the state's governor central to where AI infrastructure gets built and how quickly.
Hinojosa campaigned on an immediate moratorium on data centres and an end to tax incentives for the buildout, CNBC reported. Her win removed a Republican governor who had welcomed the industry to a state the network described as a key tech hub. Abbott had been seen as the prohibitive favourite earlier this year, the BBC reported.
Scott Ladner, chief investment officer at Horizon Investments, framed the issue as a question of geography. "There is a legitimate question about, where do you build these data centers?" he told CNBC during the overnight move.
Companies with Texas ties sold off in overnight trading on Robinhood. SpaceX fell 4.8%, Tesla more than 4% and CoreWeave 3.4%, CNBC reported. Elon Musk said in 2024 that he would move both Tesla and SpaceX to Texas from California.
State races matter because permitting, tax abatements and grid connections are decided below the federal level. Goldman Sachs told clients a Democratic Congress "might limit data center tax incentives, but a national moratorium looks unlikely in any election outcome", CNBC reported.
The same dynamic appeared elsewhere. Euronews noted that opposition to data centres featured in Ohio's Senate race, where Sherrod Brown defeated Republican Jon Husted. Local objections are becoming a national variable for the industry.
A state moratorium would not stop existing sites. It would change where the next tranche of capacity lands, at a moment when hyperscalers are trying to bring gigawatts online quickly.
What can a Democratic Congress actually do about AI?
Congress cannot switch off data centres. It can change how they are taxed, funded and investigated, and those levers are enough to move valuations.
Tax is the most direct lever. Accelerated depreciation and local abatements have lowered the cost of building server halls. Goldman's note suggests federal incentives face more scrutiny under Democratic control, though the bank stopped short of predicting a national ban.
Oversight is the second. Committee chairs can subpoena documents and call hearings, and the incoming House oversight chairman has signalled he will use that power. Robert Garcia responded to the results with a two-word statement: "Lawyer up." Wired reported.
Committee jurisdiction will shape the agenda. Energy and Commerce oversees much of technology policy in the House, while the Judiciary committees handle antitrust and competition. Wired reported that top House Democrats ended the night preparing an aggressive oversight campaign against the administration.
Appropriations are the third. A Democratic Congress will shape spending on grid upgrades, energy research and defence, and it can attach conditions to the agencies that regulate AI. Healthcare is likely to be the biggest focus, with Democrats pushing to restore expanded Affordable Care Act subsidies, CNBC's analysts said.
Crypto and banking are also in play. Euronews noted that the outcome could affect regulation of cryptocurrencies and the financial sector, two areas where the Trump administration had favoured lighter rules. Democrats could also pursue caps on credit card interest rates, an idea Trump has floated, CNBC reported.
A majority is not a free hand. Chris Weston of Pepperstone told AFP that Democratic control "would increase the potential for legislative gridlock, fiscal brinkmanship, debt-ceiling disputes, and congressional investigations".
He added that "the president would retain considerable executive authority, so the implications for individual sectors are far from straightforward". Export controls, tariffs and federal permitting largely sit with the White House, not Capitol Hill.
Why was the AI trade already fragile before the vote?
The election landed on a market already repricing AI spending. Meta, Alphabet, Oracle, Amazon and Microsoft have committed about $800bn between them to AI in 2026, the BBC reported.
Returns have not arrived on schedule. Alphabet lost more than $500bn in market value in a single day after saying AI search summaries were hurting advertising revenue. It expects to spend up to $205bn this year on investments, almost all of it related to AI.
Intel fell 28% in a session after guiding to weaker revenue, shedding more than $130bn in value, the BBC reported. Reddit dropped 29% after weak user numbers and a warning that AI search was cutting referral traffic.
Amazon has committed $220bn this year and said it spent more cash than it generated, the BBC reported. Microsoft, Meta and Oracle are in the same spending race, which is why a political shock hits the whole group rather than one company.
Apple added to the pressure on Tuesday. Its shares fell 1.9% after it gave a margin forecast that disappointed investors and blamed higher memory prices, the Guardian reported.
The company reported September-quarter revenue of $114.5bn, up 12%, and a gross margin of 47.9%, including a one-point boost from tariff refunds. Diluted earnings per share were $2.10, according to its results release.
Memory is now a cost problem across the industry. Apple has warned of an "unprecedented" rise in memory chip prices, the Guardian reported. That matters for AI because accelerator shipments depend on high-bandwidth memory, and the same supply tightness affects servers and laptops.
Put together, the selloff that began in late October was driven by doubts about AI payback, not politics. The midterm result gave investors a second reason to trim exposure to the same companies.
What does history say about markets after midterms?
Not much in the first days. A CNBC analysis of S&P 500 returns after elections from 1980 to 2024 found the index rose an average of 0.2% one day after a midterm and 1.1% after a month.
A year later it averaged a 13.7% gain, and returns were positive in 91% of cases. The index was higher a year after all 11 midterms from 1982 through 2022.
Divided government has been kinder than unified control. Across 15 elections that left no single party in charge, the S&P 500 rose an average of 15% in the following year, against 11.5% after elections that produced single-party control, CNBC found.
The closest precedent is awkward for Democrats. After the three midterms when they held both chambers and a Republican was president, in 1986, 1990 and 2006, the S&P 500 fell 0.5% on the reaction day. It then rose 3.4% after a month and 10.9% after a year.
Ryan Detrick, chief market strategist at Carson Group, told CNBC that markets tend to feel relief once an election is over. Jonathan Krinsky of BTIG warned the usual pattern may not hold, because stocks were strong into this vote rather than weak.
Société Générale has argued that Federal Reserve policy and the earnings cycle matter more than election results. In 2018, when Democrats took the House, the S&P 500 fell 6.2% for the year as the Fed raised rates four times. It was up 11.7% a year after the election.
The range of outcomes is wide. The S&P 500 fell 22.1% in the year after the 2000 election during the dotcom bust and rose 38.3% after the 2020 election, CNBC found. Elections coincided with both moves without causing them.
Chris Weston of Pepperstone told AFP that a narrow blue wave may already be priced in. He said a commanding one "could force markets to rethink Trump's remaining policy agenda and the political trajectory into 2028".
JPMorgan told clients a blue wave could knock about 0.5% off the S&P 500 on Wednesday. That is smaller than the overnight moves in Asian chip stocks, which suggests the sector-specific reaction matters more than the index call.
What should AI investors watch next?
Four variables matter more than the result itself.
The US open on Wednesday is the first test. Futures already point lower, and AI names carry the most weight in the main indices, so a modest index decline can hide a sharp move in semiconductors.
Texas is the second. Watch how quickly Hinojosa's office writes a moratorium, whether the legislature funds or blocks it, and what happens to existing abatements. Wells Fargo's 27% figure explains why the details will be read closely.
Congress is the third. Committee hearings and subpoenas will signal which companies face scrutiny. Any tax bill that touches depreciation for server halls would matter more than a hearing.
Earnings and rates are the fourth. AI capital spending guidance, memory costs and the 10-year yield have driven more of the selloff than politics.
The midterms changed who runs Congress. They did not change the arithmetic of AI capital spending: companies have promised hundreds of billions, investors want returns, and the cost of memory and power keeps rising.
Politics can accelerate or slow the buildout at the edges. Analysts do not expect it to cancel the buildout outright, even with a Texas governor who campaigned against it.
- •S&P 500 futures were down 0.34% and Nasdaq-100 futures 0.48% early on Wednesday.
- •The Nikkei 225 fell 4.45%, its lowest level since May.
- •The 10-year Treasury yield slipped to 4.902% as investors bought bonds.
- •Texas holds about 27% of US data centre capacity in gigawatts.