Form 4: Amprius CTO Sells Shares Under 10b5-1 Plan

Amprius Technologies' Chief Technology Officer, Stefan Constantin Ionel, executed planned sales of common stock and exercised options totaling over $6.7 million.

Summary

• Stefan Constantin Ionel, Chief Technology Officer of Amprius Technologies, Inc. (AMPX), reported a series of transactions involving the company's common stock.
• These transactions, which included both the exercise of stock options and the sale of common stock, occurred on January 21, 22, and 23, 2026.
• All reported exercises and sales were executed pursuant to a Rule 10b5-1 trading plan, which was adopted by Mr. Ionel on September 11, 2025.
• Mr. Ionel exercised stock options to acquire a total of 567,607 shares of common stock at exercise prices ranging from $0.05 to $0.62 per share.
• Concurrently, Mr. Ionel sold a total of 567,707 shares of common stock at average execution prices ranging from $12.00 to $12.0365 per share.
• Following these transactions, Mr. Ionel's direct beneficial ownership stands at 748,696 shares of common stock, which includes 585,697 restricted stock units.

Sentiment

Score: 6

Explanation: The sentiment is moderately positive. While there is significant insider selling, it's part of a pre-arranged 10b5-1 plan, which mitigates negative interpretations. The insider is monetizing gains from low-cost options, which is a normal part of executive compensation and wealth management.

Positives

• The Chief Technology Officer exercised stock options at very low prices (ranging from $0.05 to $0.62 per share), indicating significant unrealized gains on his equity awards.
• Sales were executed at favorable average prices (ranging from $12.00 to $12.0365 per share), allowing the insider to monetize a portion of his equity at a strong valuation.
• The transactions were conducted under a pre-arranged Rule 10b5-1 trading plan, which suggests a structured approach to personal financial management rather than a reaction to immediate market conditions or non-public information.

Negatives

• Significant insider selling, even if planned, can sometimes be perceived negatively by the market as it reduces the insider's direct equity stake in the company.

Future Outlook

NA

Industry Context

NA

Stakeholder Impact

• Shareholders may observe a reduction in the CTO's direct common stock holdings, potentially influencing market perception of insider confidence, although this is mitigated by the pre-arranged 10b5-1 plan.
• The transactions represent a monetization event for a key executive, which is a standard component of executive compensation and personal financial planning.

Key Dates

Recommendation

The Form 4 filing details pre-planned insider transactions (option exercises and subsequent sales) by the CTO. While significant selling by an insider can sometimes be a bearish signal, the execution under a Rule 10b5-1 plan adopted months prior suggests these are routine wealth management activities rather than a reaction to new, negative information. The insider is monetizing substantial gains from low-cost options. Without additional financial or operational context, this filing alone does not warrant a change from a 'hold' position, as it primarily reflects an executive's personal financial planning rather than a direct statement on the company's immediate prospects.

Keywords

Amprius Technologies, AMPX, Insider Trading, Form 4, Stock Options, Rule 10b5-1, CTO, Stefan Constantin Ionel, Equity Sales, Restricted Stock Units