AI Infrastructure, Quantum Computing and Telecom & Networking Lead Today's Stock Gainers · Sep 17, 2026

Which US stocks moved most on September 17, 2026, the themes that drove them, and the news behind each move.

1. Market at a glance

- S&P 500 (SPY) 762.70 ▲ +0.6% - Nasdaq 100 (QQQ) 716.92 ▲ +1.2% - Russell 2000 (IWM) 285.38 ▼ −0.8% - Dow (DIA) 518.26 ▼ −0.5%

2. Biggest movers, grouped by what drove them

🤖 AI Infrastructure — AI server stocks rallied as the hardware bid broadens, with Hewlett Packard Enterprise jumping 9% and Super Micro climbing on infrastructure wins. - SMCI +9.5% — Super Micro Computer, Inc. - APLD +8.2% — Applied Digital Corporation - HPE +8.0% — Hewlett Packard Enterprise Company ⚛️ Quantum Computing — Quantum stocks surged as AI slowdown fears drive investors toward quantum-connected opportunities alongside AI infrastructure. - IONQ +9.6% — IonQ, Inc. - QBTS +8.7% — D-Wave Quantum Inc. - RGTI +8.1% — Rigetti Computing, Inc. 📡 Telecom & Networking — Nokia jumped as Microsoft AI data partnership expands, boosting optical networking and telecom network automation capabilities. - SWKS +6.7% — Skyworks Solutions, Inc. - GFS +6.5% — GLOBALFOUNDRIES Inc. - NOK +4.6% — Nokia Oyj 🚀 Space & Satellites — Rocket Lab climbed 6% as the FCC cleared the first hurdle on its Iridium deal, advancing its component portfolio for space market growth. - RKLB +6.5% — Rocket Lab Corporation - ASTS +5.8% — AST SpaceMobile, Inc. ⚕️ AI Healthcare — Tempus AI surged 14.8% on revenue optimism and secured up to $9.5 million in ARPA-H funding to deploy autonomous AI in cardiology. - TEM +14.8% — Tempus AI, Inc. ⛏️ Precious Metals — Hecla Mining and Coeur Mining spiked as Treasury buyback plan ignites precious metals rally, with silver miners sitting on record cash hoards. - HL +5.4% — Hecla Mining Company - CDE +5.3% — Coeur Mining, Inc. ₿ Crypto & Digital Assets — Circle and crypto treasury firms rallied as SEC opens tokenized stock path and BlackRock-Visa partnership launches Arc platform. - PURR +12.2% — Hyperliquid Strategies Inc. - RIOT +7.5% — Riot Platforms, Inc. - WULF +7.0% — TeraWulf Inc. - CRCL +5.8% — Circle Internet Group - MARA +5.4% — MARA Holdings, Inc. - BMNR +4.7% — Bitmine Immersion Technologies, Inc. 📊 Low-Priced Small Caps — No news attached — a flow move, not a catalyst. - AEMD +374.1% — Aethlon Medical, Inc. - DAIC +163.7% — CID HoldCo, Inc. - OKLO +11.3% — Oklo Inc. - FPS +9.4% — Forgent Power Solutions, Inc. - SMR +9.2% — NuScale Power Corporation - AXTI +5.4% — AXT, Inc. - NOK +4.6% — Nokia Oyj

3. What drove the upside

- AI Server Stocks Rally as the Hardware Bid Broadens: Hewlett Packard Enterprise Jumps 9%, Super Micro Climbs 6%, Dell Rises 3% - AI Slowdown Fears Rise: Buy NVIDIA, HPE That Connect AI and Quantum - Nokia stock jumps as Microsoft AI data partnership expands - Rocket Lab Jumps 6% as FCC Clears First Hurdle on Iridium Deal; Iridium Communications Barely Budges

4. What weighed on it

- CRWV −4.2% — CoreWeave, Inc. - CMCSA −3.5% — Comcast Corporation - One group moved with no news attached — flow, not a catalyst.

5. How this was built

Warrants and leveraged ETFs were removed before grouping — they crowd out the underlying names they track. 50 tickers survived that filter. Every number here comes from market data. The theme names and the one-line explanations are written from the day's headlines — where a group moved with no headline behind it, we say so rather than inventing a reason. This is an observation of what moved, not advice and not a recommendation. This tells you where attention went today; it does not tell you what happens next.