Amprius Technologies (NYSE: AMPX) insiders, primarily CTO Constantin Stefan, have been selling shares. However, the news is not a red flag for investors, as the sales were executed under a 10b5-1 Trading Plan. These prearranged trading plans enable insiders of publicly traded companies to make periodic sales of their stock. The plans usually coincide with share-based compensation and are a way for insiders to reap the rewards of their work. As of late January 2026, AMPX stock's price has increased over 400% from its lows in 2025, offering strong reasons to realize profits, such as portfolio diversification and managing tax liabilities from option exercises.
The critical takeaway is that insiders still own nearly 13% of the stock, and other forces, including institutional and analyst trends, suggest it is being accumulated despite the insider selling. Institutional ownership is still low, there are lingering concerns about cash burn and scalability, but it is improving. InsiderTrades data reveals institutional ownership creeping higher, with activity ramping at the end of 2025. The Q4 balance has buying outpacing selling by more than $27 bought for each $1 sold, and a bullish bias was maintained in early 2026.
