Amprius CTO Sells Nearly 40,000 Shares Amid Growth
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Feb 08 2026
0mins
Should l Buy AMPX?
Source: NASDAQ.COM
- Executive Sell-off: On January 28, 2026, Amprius CTO Constantin Ionel Stefan sold 39,690 shares for $476,351, representing 5.03% of his direct holdings, reducing his position to 748,696 shares, indicating he still retains significant confidence in the company.
- Transaction Context: The sale was an option exercise followed by immediate disposition, with the trade size exceeding Mr. Stefan's historical median, reflecting substantial prior dispositions and suggesting a cautious financial strategy amid market fluctuations.
- Company Performance Highlights: Amprius achieved a remarkable 173% year-over-year revenue growth in Q3 2026, reaching $21.4 million, primarily driven by soaring demand for its high-performance lithium-ion batteries in the aerospace and defense sectors, showcasing the company's market potential in electrification and lightweight energy solutions.
- Market Valuation Considerations: Although Amprius shares are well above the 52-week low of $1.70 and the price-to-sales ratio exceeds 25, indicating a high valuation, Mr. Stefan's sell-off is viewed as a prudent move at elevated prices, suggesting investors may want to wait for a price dip before considering entry.
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Analyst Views on AMPX
Wall Street analysts forecast AMPX stock price to rise
4 Analyst Rating
4 Buy
0 Hold
0 Sell
Strong Buy
Current: 10.190
Low
17.00
Averages
19.00
High
20.00
Current: 10.190
Low
17.00
Averages
19.00
High
20.00
About AMPX
Amprius Technologies, Inc. develops, manufactures and markets lithium-ion batteries for mobility applications, including the aviation, electric vehicle (EV) and light electric vehicle (LEV) industries. The Company’s commercially available SiMaxx batteries deliver up to 450 Wh/kg and 1,150 Wh/L, with third-party validation of 500 Wh/kg and 1,300 Wh/L. Its batteries are primarily used for existing and emerging aviation applications, including unmanned aerial systems (UAS), such as drones and high-altitude pseudo satellites (HAPS). It offers high-performance silicon anode batteries under product platforms: SiCore and SiMaxx. Its SiCore batteries are based on an innovative, proprietary silicon anode material system delivering high-energy-density silicon anode batteries that surpass current graphite cell performance. Its SiMaxx high-energy battery cells are designed to maximize specific energy for applications with low power requirements.
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
Amprius CTO Sells Nearly 40,000 Shares Amid Stock Surge
- Significant Transaction Size: Amprius Technologies' CTO, Dr. Constantin Ionel Stefan, exercised options and sold 39,690 shares on January 28, 2026, totaling $476,351, indicating his active role in the market and confidence in the company's prospects.
- Reduction in Holdings: This transaction resulted in a 5.03% decrease in Dr. Stefan's direct holdings, now at 748,696 shares, reflecting a significant shrinkage in his available holding base, which may impact future selling capacity.
- Strong Market Performance: Amprius's stock price surged 358.75% over the past year, with this transaction occurring at a high point, showcasing robust demand and growth potential in the electric vehicle and aerospace sectors.
- Investor Confidence: Despite selling nearly 40,000 shares, Dr. Stefan retains close to 750,000 shares, indicating sustained confidence in the company's future, and the transaction was executed under a Rule 10b5-1 trading plan, mitigating insider trading risks.
See More
Amprius CTO Sells Nearly 40,000 Shares Amid Growth
- Executive Sell-off: On January 28, 2026, Amprius CTO Constantin Ionel Stefan sold 39,690 shares for $476,351, representing 5.03% of his direct holdings, reducing his position to 748,696 shares, indicating he still retains significant confidence in the company.
- Transaction Context: The sale was an option exercise followed by immediate disposition, with the trade size exceeding Mr. Stefan's historical median, reflecting substantial prior dispositions and suggesting a cautious financial strategy amid market fluctuations.
- Company Performance Highlights: Amprius achieved a remarkable 173% year-over-year revenue growth in Q3 2026, reaching $21.4 million, primarily driven by soaring demand for its high-performance lithium-ion batteries in the aerospace and defense sectors, showcasing the company's market potential in electrification and lightweight energy solutions.
- Market Valuation Considerations: Although Amprius shares are well above the 52-week low of $1.70 and the price-to-sales ratio exceeds 25, indicating a high valuation, Mr. Stefan's sell-off is viewed as a prudent move at elevated prices, suggesting investors may want to wait for a price dip before considering entry.
See More
Amprius CTO Sells Nearly 40,000 Shares Amid Stock Surge
- Transaction Scale Analysis: On January 28, 2026, Amprius Technologies' CTO Constantin Ionel Stefan exercised options and sold 39,690 shares for $476,351, significantly exceeding his historical median sale of 14,276 shares, indicating a notable reduction in his holding capacity.
- Impact of Holdings Change: Post-transaction, Stefan's direct holdings decreased to 748,696 shares, suggesting that his available shares are now less than half of what they were at the start of the recent period, which may affect market expectations for future sales.
- Market Performance Correlation: This transaction occurred during a period when Amprius's stock price appreciated by 358.75% over the past year, indicating that Stefan aimed to maximize proceeds from option conversion amid strong demand in the electric vehicle and aerospace sectors.
- Investor Considerations: Despite selling nearly 40,000 shares, Stefan retains almost 750,000 shares, reflecting confidence in the company's future, and the transaction was executed under a Rule 10b5-1 trading plan, mitigating insider trading risks.
See More
Amprius Partners with Nanotech Energy to Enhance Production Capacity
- Strategic Partnership: Amprius has entered a strategic manufacturing partnership with U.S.-based Nanotech Energy to enhance domestic production capabilities for its high-performance silicon-anode cells, thereby strengthening supply chain security for critical applications.
- Customer Validation: The collaboration has already received validation from key customers, including L3Harris Technologies, indicating its potential in defense and aerospace markets, further solidifying Amprius's market position in these sectors.
- Battery Performance Enhancement: Amprius's SA128 silicon-anode cell features a 21700 cylindrical format, a capacity of 6.8 Ah, and an energy density of 320 Wh/kg, providing a scalable, high-performance solution for commercial, industrial, and defense markets.
- Positive Market Reaction: Following the announcement, Amprius's stock traded over 11% higher by Tuesday mid-morning, reflecting strong market optimism regarding the partnership, with retail sentiment shifting from 'bullish' to 'extremely bullish'.
See More
Amprius Technologies Forms Strategic Partnership with Nanotech Energy
- Supply Chain Enhancement: Amprius Technologies' strategic manufacturing partnership with Nanotech Energy will establish a domestic supply chain for silicon battery production, significantly boosting the ability to meet key customer demands, including L3Harris Technologies.
- Capacity Expansion Plans: This collaboration is set to increase Amprius' global capacity beyond 2.0 GWh, addressing the rising demand for batteries across commercial, industrial, and defense sectors, marking a significant step in scaling domestic production.
- Alignment with National Security: The partnership aligns with the updated National Defense Authorization Act, emphasizing the importance of domestic supply chains in defense and aerospace sectors, thereby enhancing Amprius' capability to meet evolving defense customer requirements.
- Positive Stock Reaction: Following the partnership announcement, Amprius' shares surged by 11.79% to $14.70, reflecting strong market approval of this strategic collaboration.
See More
Amprius Partners with Nanotech Energy to Establish U.S. Supply Chain for High-Performance Cells
- U.S. Supply Chain Establishment: Amprius has formed a manufacturing partnership with Nanotech Energy to secure a domestic production pathway for high-performance silicon batteries, supporting key customers like L3Harris, thereby enhancing the company's competitiveness in defense and aerospace markets.
- Technical Collaboration Advantage: As Amprius' first U.S.-based manufacturing partner, Nanotech Energy brings deep expertise in advanced lithium-ion battery development and manufacturing, enabling Amprius to swiftly transition from R&D to production while ensuring product quality and security.
- Battery Specification Enhancement: The specifications for the Amprius SA128 silicon-anode cell include a 21700 cylindrical format, a capacity of 6.8 Ah, and an energy density of 320 Wh/kg, meeting stringent requirements from defense customers and further driving the company's market share in commercial and industrial sectors.
- Global Capacity Expansion: The partnership with Nanotech allows Amprius to increase its global capacity beyond 2.0 GWh, strengthening its position in the rapidly growing battery market while supporting the demands of national security programs.
See More
Amprius CTO Sells Nearly 40,000 Shares Amid Stock Surge
- Significant Transaction Size: Amprius Technologies' CTO, Dr. Constantin Ionel Stefan, exercised options and sold 39,690 shares on January 28, 2026, totaling $476,351, indicating his active role in the market and confidence in the company's prospects.
- Reduction in Holdings: This transaction resulted in a 5.03% decrease in Dr. Stefan's direct holdings, now at 748,696 shares, reflecting a significant shrinkage in his available holding base, which may impact future selling capacity.
- Strong Market Performance: Amprius's stock price surged 358.75% over the past year, with this transaction occurring at a high point, showcasing robust demand and growth potential in the electric vehicle and aerospace sectors.
- Investor Confidence: Despite selling nearly 40,000 shares, Dr. Stefan retains close to 750,000 shares, indicating sustained confidence in the company's future, and the transaction was executed under a Rule 10b5-1 trading plan, mitigating insider trading risks.
See More
Amprius CTO Sells Nearly 40,000 Shares Amid Growth
- Executive Sell-off: On January 28, 2026, Amprius CTO Constantin Ionel Stefan sold 39,690 shares for $476,351, representing 5.03% of his direct holdings, reducing his position to 748,696 shares, indicating he still retains significant confidence in the company.
- Transaction Context: The sale was an option exercise followed by immediate disposition, with the trade size exceeding Mr. Stefan's historical median, reflecting substantial prior dispositions and suggesting a cautious financial strategy amid market fluctuations.
- Company Performance Highlights: Amprius achieved a remarkable 173% year-over-year revenue growth in Q3 2026, reaching $21.4 million, primarily driven by soaring demand for its high-performance lithium-ion batteries in the aerospace and defense sectors, showcasing the company's market potential in electrification and lightweight energy solutions.
- Market Valuation Considerations: Although Amprius shares are well above the 52-week low of $1.70 and the price-to-sales ratio exceeds 25, indicating a high valuation, Mr. Stefan's sell-off is viewed as a prudent move at elevated prices, suggesting investors may want to wait for a price dip before considering entry.
See More
Amprius CTO Sells Nearly 40,000 Shares Amid Stock Surge
- Transaction Scale Analysis: On January 28, 2026, Amprius Technologies' CTO Constantin Ionel Stefan exercised options and sold 39,690 shares for $476,351, significantly exceeding his historical median sale of 14,276 shares, indicating a notable reduction in his holding capacity.
- Impact of Holdings Change: Post-transaction, Stefan's direct holdings decreased to 748,696 shares, suggesting that his available shares are now less than half of what they were at the start of the recent period, which may affect market expectations for future sales.
- Market Performance Correlation: This transaction occurred during a period when Amprius's stock price appreciated by 358.75% over the past year, indicating that Stefan aimed to maximize proceeds from option conversion amid strong demand in the electric vehicle and aerospace sectors.
- Investor Considerations: Despite selling nearly 40,000 shares, Stefan retains almost 750,000 shares, reflecting confidence in the company's future, and the transaction was executed under a Rule 10b5-1 trading plan, mitigating insider trading risks.
See More
Amprius Partners with Nanotech Energy to Enhance Production Capacity
- Strategic Partnership: Amprius has entered a strategic manufacturing partnership with U.S.-based Nanotech Energy to enhance domestic production capabilities for its high-performance silicon-anode cells, thereby strengthening supply chain security for critical applications.
- Customer Validation: The collaboration has already received validation from key customers, including L3Harris Technologies, indicating its potential in defense and aerospace markets, further solidifying Amprius's market position in these sectors.
- Battery Performance Enhancement: Amprius's SA128 silicon-anode cell features a 21700 cylindrical format, a capacity of 6.8 Ah, and an energy density of 320 Wh/kg, providing a scalable, high-performance solution for commercial, industrial, and defense markets.
- Positive Market Reaction: Following the announcement, Amprius's stock traded over 11% higher by Tuesday mid-morning, reflecting strong market optimism regarding the partnership, with retail sentiment shifting from 'bullish' to 'extremely bullish'.
See More
Amprius Technologies Forms Strategic Partnership with Nanotech Energy
- Supply Chain Enhancement: Amprius Technologies' strategic manufacturing partnership with Nanotech Energy will establish a domestic supply chain for silicon battery production, significantly boosting the ability to meet key customer demands, including L3Harris Technologies.
- Capacity Expansion Plans: This collaboration is set to increase Amprius' global capacity beyond 2.0 GWh, addressing the rising demand for batteries across commercial, industrial, and defense sectors, marking a significant step in scaling domestic production.
- Alignment with National Security: The partnership aligns with the updated National Defense Authorization Act, emphasizing the importance of domestic supply chains in defense and aerospace sectors, thereby enhancing Amprius' capability to meet evolving defense customer requirements.
- Positive Stock Reaction: Following the partnership announcement, Amprius' shares surged by 11.79% to $14.70, reflecting strong market approval of this strategic collaboration.
See More
Amprius Partners with Nanotech Energy to Establish U.S. Supply Chain for High-Performance Cells
- U.S. Supply Chain Establishment: Amprius has formed a manufacturing partnership with Nanotech Energy to secure a domestic production pathway for high-performance silicon batteries, supporting key customers like L3Harris, thereby enhancing the company's competitiveness in defense and aerospace markets.
- Technical Collaboration Advantage: As Amprius' first U.S.-based manufacturing partner, Nanotech Energy brings deep expertise in advanced lithium-ion battery development and manufacturing, enabling Amprius to swiftly transition from R&D to production while ensuring product quality and security.
- Battery Specification Enhancement: The specifications for the Amprius SA128 silicon-anode cell include a 21700 cylindrical format, a capacity of 6.8 Ah, and an energy density of 320 Wh/kg, meeting stringent requirements from defense customers and further driving the company's market share in commercial and industrial sectors.
- Global Capacity Expansion: The partnership with Nanotech allows Amprius to increase its global capacity beyond 2.0 GWh, strengthening its position in the rapidly growing battery market while supporting the demands of national security programs.
See More
