Biggest stock movers Tuesday: NVTS, PII, and more

Stock futures dipped in the premarket hours of Tuesday as market participants awaited the release of earnings reports from major banks and prepared for Federal Reserve Chair Jerome Powell’s remarks later in the day. 

Here are some of Tuesday's biggest stock movers:

Biggest stock gainers

• Navitas Semiconductor (NASDAQ:NVTS) +25% - Shares advanced after the company reported progress in developing medium- and high-voltage 800 VDC GaN and SiC power devices designed for Nvidia’s (NVDA) next-generation AI factory computing platforms. Its new 100 V GaN FET portfolio, alongside 650 V GaN and high-voltage SiC devices, targets Nvidia’s 800 VDC AI architecture, promising improved efficiency, power density, and performance. “As NVIDIA drives transformation in AI infrastructure, we’re proud to support this shift with advanced GaN and SiC power solutions that enable the efficiency, scalability, and reliability required by next-generation data centers,” said Navitas CEO Chris Allexandre.
• Polaris (NYSE:PII) +11% - Shares jumped after announcing plans to sell a majority stake in its Indian Motorcycle business to Carolwood LP, a Los Angeles-based private equity firm, with the deal expected to close in Q1 2026 pending regulatory approvals. Polaris will retain a minority stake and expects the separation to sharpen its focus on higher-growth areas, free up capital, and unlock long-term shareholder value. Indian Motorcycle contributed ~$478M in revenue over the past 12 months, roughly 7% of Polaris’ total. The transaction is projected to boost annualized adjusted EBITDA by ~$50M and raise adjusted EPS by about $1. Preliminary Q3 results indicate strong retail momentum and operational improvements, with sales expected at the high end of guidance ($1.6–$1.8B) and adjusted EPS surpassing earlier forecasts; final results are due October 28.

Biggest stock losers

• Orion S.A. (NYSE:OEC) -17% - Shares dipped after releasing a preliminary, unaudited Q3 financial update that included another significant cut to its full-year guidance. The company now expects third-quarter adjusted EBITDA to be approximately $55M as compared to $80.1M a year ago. This development resulted in a sharply lowered full-year 2025 adjusted EBITDA forecast of $220M–$235M, representing the third downgrade from its initial $290M–$330M guidance given at the end of 2024, and well below last year's $302.2M. Results were weighed down by lower Western market rubber volumes, oil-driven inventory revaluation, inventory drawdowns affecting fixed cost absorption, and an unfavorable specialty mix.