Heartflow Jumps 36% as Medical AI Leads Today's Stock Gainers · Aug 14, 2026

Which US stock themes moved on August 14, 2026, which names led them, and the news behind each move.

1. Market at a glance

- S&P 500 (SPY) 776.34 ▲ +0.4% - Nasdaq 100 (QQQ) 731.07 ▲ +1.1% - Russell 2000 (IWM) 305.06 ▲ +1.2% - Dow (DIA) 536.80 ▼ −0.5%

2. Biggest movers, grouped by what drove them

🤖 AI Infrastructure — MaxLinear surged on expanded AI infrastructure control-plane portfolio and optical AI data center growth, while Applied Optoelectronics rallied as part of a broad optics boom tied to AI infrastructure demand. - AAOI +15.5% — Applied Optoelectronics, Inc. - MXL +10.7% — MaxLinear, Inc. 💊 Medical AI — HeartFlow jumped 35.7% after raising full-year 2026 guidance on 48% revenue surge, reinforcing its AI-powered coronary artery disease management platform as the standard. - HTFL +35.7% — Heartflow, Inc. ⚛️ Nuclear Energy — Standard Nuclear climbed as it nears commercial TRISO fuel production with expanding licensing and construction milestones across its nuclear fuel production footprint. - STDN +10.1% — Standard Nuclear, Inc. 🧬 Biotech — Vera Therapeutics surged after FDA accelerated approval of TRUTAKNA for IgA nephropathy, transforming the investment case for the rare kidney disease treatment. - VERA +9.5% — Vera Therapeutics, Inc. - IOVA +7.1% — Iovance Biotherapeutics, Inc. 💰 Fintech — Nu Holdings jumped to a five-month high after clearing $1 billion in quarterly profit for the first time, with Q2 earnings focusing on margins and AI expansion into Mexico. - NU +9.3% — Nu Holdings Ltd. 📈 Index Inclusion — Reddit surged 14% on landmark entry into the S&P 500 next week, a major milestone for the social media platform. - RDDT +12.6% — Reddit, Inc. 📊 Low-Priced Small Caps — No news attached — a flow move, not a catalyst. - WING +11.1% — Wingstop Inc. - BYND +10.3% — Beyond Meat, Inc. - ALM +9.0% — Almonty Industries Inc. - NBIS +8.9% — Nebius Group N.V. - AEHR +8.7% — Aehr Test Systems, Inc. - LUNR +8.3% — Intuitive Machines, Inc. - ASTH +8.0% — Astrana Health, Inc.

3. What drove the upside

- MaxLinear Introduces RackCommander™ Control-Plane Portfolio for Next-Generation AI Infrastructure - Heartflow Reports Second Quarter 2026 Financial Results and Raises Full Year 2026 Guidance - Standard Nuclear Announces Licensing and Construction Milestones Across Expanding Nuclear Fuel Production Footprint - Vera Therapeutics Wins FDA Approval for TRUTAKNA in IgA Nephropathy, Sets Launch

4. What weighed on it

- BLSH −11.2%, Bullish - UCTT −8.6%, Ultra Clean Holdings, Inc. - 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.