Form 4: Amprius Director Sells $4.1M in Stock via 10b5-1 Plan

Amprius Technologies Director and 10% owner Kang Sun reported the sale of 217,869 common shares totaling approximately $4.1 million through a pre-arranged Rule 10b5-1 trading plan.

Summary

• Kang Sun, a Director and 10% owner of Amprius Technologies, Inc. (AMPX), reported the sale of common stock.
• The transactions occurred on March 23, 2026, and were executed under a Rule 10b5-1 trading plan adopted on August 18, 2025.
• A total of 152,823 shares were sold at an average price of $18.6863 per share, with prices ranging from $17.89 to $18.88.
• An additional 65,046 shares were sold at an average price of $19.0589 per share, with prices ranging from $18.89 to $19.36.
• The total value of shares sold amounts to approximately $4,096,999.98.
• Following these transactions, Kang Sun directly holds 1,342,400 shares, which includes 1,159,385 restricted stock units.
• Indirect beneficial ownership through the KANG & CECILLIA SUN FAMILY REVOCABLE TRUST stands at 177,858 shares.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral to slightly negative event. While the sale by a director and 10% owner is significant, the execution under a Rule 10b5-1 plan mitigates the negative signal, suggesting a pre-planned liquidity event rather than a reaction to adverse company news.

Positives

• The sales were conducted under a pre-arranged Rule 10b5-1 trading plan, indicating a planned divestment rather than an immediate reaction to new, undisclosed information.

Negatives

• A Director and 10% owner selling a significant number of shares (217,869 shares) could be perceived as a negative signal by some investors, even if pre-planned.
• The total value of shares sold is approximately $4.1 million, representing a substantial divestment.

Future Outlook

NA

Industry Context

StockSavvy.ai notes that insider sales, even when pre-planned via a 10b5-1 plan, are routinely monitored by investors for potential signals regarding management's confidence in the company's future prospects. In the high-growth battery technology sector, such transactions are often scrutinized against the backdrop of capital needs and competitive landscape.

Related Party Transactions

• Indirect beneficial ownership of 177,858 shares is held by the KANG & CECILLIA SUN FAMILY REVOCABLE TRUST, for which the reporting person, Kang Sun, and his spouse are co-trustees.

Stakeholder Impact

• Shareholders: May interpret the insider sale as a lack of confidence, potentially leading to short-term price volatility, though the 10b5-1 plan context softens this impact.

Key Dates

Recommendation

While the sale by a director and 10% owner could be seen as a negative signal, the execution under a pre-arranged 10b5-1 plan suggests a planned liquidity event rather than a reaction to new, adverse information. Given the context, a 'hold' recommendation is appropriate as this filing alone does not provide sufficient new information to warrant a change in investment thesis, but it does warrant continued monitoring of insider activity and company fundamentals.

Keywords

Amprius Technologies, AMPX, Kang Sun, Insider Sale, Form 4, 10b5-1 Plan, Director Stock Sale, Beneficial Ownership, Restricted Stock Units, Battery Technology