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What the midterms mean for storage stocks and AI companies

On 4 November 2026 the S&P 500 rose 1.6% while memory and storage stocks fell 7% to 8%, as investors priced a risk to the AI data-center build-out. What moved, why, and what to watch.

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The 2026 midterms hit storage stocks and AI chip companies even as the wider market rose: on 4 November, the day after Democrats were projected to win both houses of Congress, the S&P 500 closed up 1.6% while Micron, SanDisk, Western Digital and Seagate fell 7% to 8%. Investors read the result as a risk to the data-center build-out that drives their sales. Most of what would cut that demand still needs states to act or the president to sign.

In short

  • Memory and storage makers sell into AI data centers, so a vote read as a brake on building them hit their shares hardest.
  • The fall came after gains of 100% to 375% in 2026 and worries that memory prices are near a peak, so it was not only about the election.
  • The market priced a risk, not a decided policy: pauses need governors and legislatures, and national rules need the president's signature.

Not advice

This note explains these moves. It isn't financial or investment advice.

What happened to storage and AI stocks after the vote?

They fell while the rest of the market rallied. Closes are from Yahoo Finance's daily price history; the 2026 gain runs from the 31 December 2025 close to election eve.

Index or stock 2026, to 3 Nov close 4 Nov 2026, close to close
S&P 500 +10.6% +1.6%
Nasdaq Composite +9.2% +1.4%
SOX (PHLX chip index) +49.7% −3.1%
SanDisk (SNDK) +374.6% −7.9%
Micron (MU) +199.6% −7.0%
Seagate (STX) +120.2% −8.1%
Western Digital (WDC) +101.6% −6.8%
NetApp (NTAP) +78.2% −1.6%
Nvidia (NVDA) +10.8% −3.2%
Microsoft (MSFT) +7.7% +6.7%

The split ran through AI itself. Microsoft, Amazon (+6.1%) and Alphabet (+3.2%) rose on 4 November, while the cloud renter CoreWeave fell 9.9%. CNBC reported that investors "feared a big Democratic win could mean more restrictions on data centers nationwide", and that Apple, a big memory buyer, hit a record high on bets that the result would ease pressure on memory prices. Reuters said hyperscalers, the biggest data-center owners, held up on bets that slower building could curb their AI spending, the spending memory makers sell into.

On 5 November the selloff spread. At 11:05 a.m. ET, Reuters reported the semiconductor index down 10.2%, with Amazon down 3.9% and Alphabet 2.7%. Those are intraday figures, not closes. By the 4 November close, SanDisk was 55.6% below its June record and Micron 34.5%, per Yahoo Finance.

Why are memory and storage makers AI stocks at all?

Because every AI model runs on data held at three speeds. Hard drives store the huge "data lakes" models are trained on, mostly on nearline drives: high-capacity disks kept online for data read now and then. Only Seagate, Western Digital and Toshiba still make them, per Wikipedia's list of manufacturers.

Faster data sits on NAND flash in enterprise SSDs, the solid-state drives in data center servers, made by SanDisk, spun off from Western Digital in 2025, and by Micron. The fastest layer is DRAM, the working memory beside each processor, and HBM, high-bandwidth memory: DRAM stacked next to an AI chip such as an Nvidia GPU. Micron competes there with Samsung and SK hynix. NetApp sells storage systems built from these parts. All three memory makers joined Anthropic's Series H in May 2026 as "strategic infrastructure partners", ahead of the Anthropic IPO.

What did the companies report just before the vote?

Sales up 55% to 379% on a year, and guidance for more, in each company's SEC filing. Micron's yearly change is computed.

Company, date reported Latest quarter revenue Change on a year Guidance, next quarter
Micron, 30 Sep 2026 $54.23B +379% $61.5B ± $1.5B
SanDisk, 29 Oct 2026 $11.031B +378% $12.2B to $12.6B
Western Digital, 22 Oct 2026 $4.381B +55% $5.1B ± $0.1B
Seagate, 27 Oct 2026 $4.233B +61% $4.8B ± $0.1B

Nothing in these reports showed demand falling before the election. SanDisk's data-center revenue was $4.802 billion, up 61% on the quarter. Seagate's Dave Mosley described "a multi-year growth phase", and Western Digital's CFO cited "robust exabyte growth and improved pricing".

How much are the hyperscalers still spending?

More than ever. The four biggest US hyperscalers gave these figures with their September-quarter results, in filings and on calls reported by CNBC.

Company 2026 capital spending July to September 2026 What it said about 2027
Microsoft about $170B (cut from $175B) $45.2B "over $50 billion" for Oct to Dec; no 2027 figure
Alphabet $195B to $205B $51.36B "increase significantly in 2027"
Amazon about $220B $77.3B "spend meaningfully more in 2027"
Meta $135B to $145B $34.91B "continue investing aggressively"

Added up, that is about $720 billion to $740 billion for 2026. TrendForce puts nine large cloud providers at $957 billion in 2026 and over $1.5 trillion in 2027. No plan changed on 3 November. The question is whether US sites can be built fast enough to spend it, which is where the AI bubble debate and cloud computing meet politics.

Who can actually slow the build-out?

Mostly states, and the new Congress only with the president. What the midterms mean for AI data centers covers the results; this is who holds which lever.

Who What it can do Example from 2026
Governors Executive-order pauses, reviews of tax breaks Georgia's Keisha Lance Bottoms said she would "sign an executive order for that pause"
State legislatures Moratoriums, subsidies, who pays for power Texas's session opens 12 January 2027
Utility commissions Grid connection rules and costs Georgia's: Democrats won a 3–2 majority on 3 November, unofficial results show
Local voters Local ballot measures On 3 November, 40 of 41 went against data centers (Ballotpedia, via CNBC)
Congress alone, from 3 January 2027 Hearings, subpoenas, Senate votes on nominees A Democratic Senate votes on Fed, SEC and FERC picks
Congress with the president New laws: a national moratorium, AI rules, taxes The Sanders and Ocasio-Cortez moratorium bill, March 2026
The president alone Tariffs, export controls, the veto A 25% [[what-is-a-tariff
Regulators Grid rules, export licenses FERC's large-load show-cause orders of 18 June 2026

The arithmetic of Congress matters most. Overriding a veto takes two-thirds of each chamber, 67 senators and 290 representatives if all vote, and the Democratic majorities are short of both: NBC News had called 54 Senate and 243 House seats for them at 11:41 a.m. ET on 5 November 2026. The fastest brakes sit with governors and legislatures, and the slowest with Washington. UBS analysts, per Reuters, estimated that around 30% of expected US data-center capacity added in 2028 could be at risk from construction pauses.

What does history say about stocks after midterms?

That the broad market has usually risen in the year after, which says little about one sector this year.

Source What it measured Result
U.S. Bank, 28 Oct 2026 12 months after 31 midterms, 1900 to 2025 average +12.4%; +17.5% since 1980
U.S. Bank 3-month S&P 500 returns since 1948, by control one party 2.42%, split 2.17%, not significant
State Street (Michael Arone), 26 Aug 2026 12-month price return after midterms average +14%; no decline since 1930
Yahoo Finance (Jared Blikre), 4 Nov 2026 End of October to next June, since 1950 up in all 19 cycles, median about 15%

U.S. Bank warns that "historical averages do not guarantee gains after the 2026 election": outcomes ranged from losses above 30% to gains near 50%, and 11 of the 31 periods came with other shocks. No source opened here breaks out a Republican president with a Democratic Congress. The figures describe the S&P 500, not memory makers.

What could happen next?

Three paths, as of 5 November 2026.

  • The pause is priced, and demand holds. Trigger: hyperscalers confirm higher 2027 spending in reports expected from late January, and Micron meets its $61.5 billion guidance.
  • US building slows, and demand moves. Trigger: governors sign pauses and legislatures pass moratoriums. Gallo Partners' Michael Alfaro told Bloomberg on 5 November that "names that already have compute are going to be the winners."
  • The memory cycle turns. Trigger: contract-price increases stall while central banks keep raising interest rates; two Fed officials backed a hike on 28 October, per Yahoo Finance.

What to watch, with dates:

  • 17 November: Nvidia's quarterly results, per Nvidia.
  • 20 November: SanDisk shares are expected to start trading after its 8-for-1 split.
  • 8 to 9 December: the Fed's last 2026 meeting, per the Federal Reserve.
  • 11 December: federal funding runs out unless the lame-duck Congress extends it.
  • Mid to late December: Micron's next results (expected; date not yet set) and TrendForce's next contract-price forecast.
  • 12 January 2027: the Texas Legislature opens, per the Legislative Reference Library.

Still argued

Is this the memory cycle's peak, or a pause? Bulls: TrendForce (30 September 2026) projects 4Q26 conventional DRAM contract prices up 10% to 15% and NAND up 15% to 20%, and (29 September) HBM prices up 121% in 2027; Micron's Sanjay Mehrotra (30 September) said "we expect an even stronger fiscal 2027." Bears: TrendForce also says conventional DRAM increases are moderating and consumer demand is weak; MRB Partners (5 November, via CNBC) said "a shakeout among the most speculative parts of the theme is underway"; Incline's Ted Parkhill (5 November, via Reuters) said the market is "moving from the promise of AI to the price of AI." Neither side has next quarter's prices yet.

Check yourself

  • Why did Microsoft rise and Micron fall on the same day, when both depend on AI?
  • Which levers over data centers can a state use without Washington, and which need the president's signature?
  • What does the history of post-midterm returns leave out about this year?

Sources

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Graphite

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