After-Hours Stock Movers:

Super Micro Computer (NASDAQ: SMCI)

Supermicro shares rocketed 20% higher following a bullish preliminary Q4 fiscal 2026 update. While fourth-quarter revenue is expected near the low end of its $11.0–$12.5 billion guidance, GAAP and non-GAAP gross margins exploded to 15%–17% (nearly doubling the guided 8.2%–8.4%) due to a favorable product and customer mix. Furthermore, record demand drove Q4 new orders above $60 billion, lifting server peers Dell Technologies (+5%) and Hewlett Packard Enterprise (+4.5%) in sympathy.

Oklo Inc. (NYSE: OKLO) & X-Energy (NASDAQ: XE)

Nuclear energy developers Oklo (+8%) and X-Energy (+12%) surged following reports that both companies are joining a $200 million federal program to accelerate nuclear reactor development for AI data centers. The initiative, alongside tech giants Microsoft and Nvidia, aims to fast-track on-site clean power generation to relieve electricity grid congestion caused by the AI boom. Official details are expected to be unveiled at an upcoming U.S. Department of Energy summit.

Pegasystems (NASDAQ: PEGA)

Pegasystems dropped 8% after missing Wall Street expectations across the board for its second quarter. The enterprise AI software provider reported Q2 EPS of $0.35 against the $0.43 consensus, while revenue came in light at $420.72 million versus $427.38 million expected. The soft quarter underscores continuing enterprise scrutiny on software IT budgets.

Celldex Therapeutics (NASDAQ: CLDX)

Celldex shares fell 8% after the company announced that its Phase 2 study evaluating subcutaneous barzolvolimab in prurigo nodularis (PN) failed to meet its primary and secondary endpoints. Despite demonstrating profound mast cell depletion, the treatment failed to deliver a statistically significant reduction in skin itch compared to placebo, indicating mast cells may not drive the disease. Celldex is discontinuing the PN trial, though barzolvolimab continues to be evaluated across other inflammatory indications.

Alaska Air Group (NYSE: ALK)

Alaska Air Group slid 4% after issuing a disappointing near-term earnings outlook. While the carrier reported Q2 adjusted EPS of -$0.92 (slightly ahead of the -$0.98 consensus) on $4.07 billion in revenue, management projected Q3 EPS of $0.00 to $1.00, well below the $1.48 consensus estimate. Higher operating costs and lingering domestic yield pressures continue to weigh on profitability.