Amprius CTO Buys Big at $0.05 After Selling Near $12: Insider Confidence Shines Amid Volatile Stock Flash

Insider Activity Snapshot

On January 21, 2026, CTO Stefan Constantin Ionel executed a Rule 10b5‑1 trading plan that saw him purchase 41,563 shares of Amprius Technologies common stock at an average price of $0.62, increasing his stake to 790,259 shares. Two days later, he added another 253,928 shares at $0.05 and 72,795 shares at $0.45, bringing his holdings to 1,075,419 shares. These purchases are notable because they come after a series of high‑price sales earlier in the month—Ionel sold 73,280 shares at $12.00 on January 22 and 492,827 shares at $12.04 on January 23, and he had sold 1,600 shares at $12.00 on January 23 as well. The net result is a significant shift from selling at near‑$12 prices to buying at sub‑$1 prices, a move that investors often interpret as a bullish signal or, at the very least, a confidence‑indicating action by an insider.

What This Means for Investors

The timing of Ionel’s purchases is telling. He has a long‑term, Rule 10b5‑1 plan in place, which removes the risk of market timing accusations and suggests that he views the current valuation—$11.95 at close—as attractive. The plan’s adoption date, September 11, 2025, indicates that the strategy was set well before the recent price volatility, further mitigating the perception of opportunistic trading. For the broader market, Ionel’s activity adds a layer of stability: if a key technologist is buying, it can temper the negative sentiment that often follows insider sales. That said, the company’s negative earnings and a price‑to‑earnings ratio of –44.18 mean that the stock remains a speculative play; Ionel’s buying alone is unlikely to swing the price dramatically without a corresponding shift in fundamentals.

A Profile of Stefan Constantin Ionel

Ionel’s historical transactions paint a picture of a disciplined, long‑term investor. In December 2025, he sold 198,255 shares at $10.51 and bought 125,000 shares at $0.05, a stark contrast that underscores a willingness to buy at low prices and sell at higher levels. His most recent activity—large sales at $12 and purchases at $0.05‑$0.45—continues this pattern. Additionally, Ionel has exercised a substantial number of stock options (125,000 shares sold as options in December 2025), indicating that he holds a sizable convertible position and is comfortable converting those options into common shares when the price dips. Over the past few months, he has consistently increased his ownership through purchases, suggesting confidence in Amprius’s long‑term technology roadmap, particularly in high‑energy lithium‑ion storage solutions that the company is positioning for electric‑vehicle and satellite markets.

Broader Insider Trends

While Ionel’s activity is significant, it is not isolated. Sun Kang, a senior executive, has been actively buying shares throughout January, with multiple purchases ranging from $1.78 to $2.50 and selling around $11.07 to $11.03. This juxtaposition of insider buying and selling reflects the broader volatility that Amprius has experienced: a 52‑week high of $16.03 versus a low of $1.70, coupled with a 30.95% monthly gain and a staggering 262.66% yearly rise. Investors should note that insider activity often trails market moves; executives may be buying or selling to hedge, diversify, or as part of a pre‑planned trading strategy, rather than reacting to immediate news.

Investor Takeaway

Amprius’s stock remains highly volatile and heavily driven by market sentiment and speculative valuation. Ionel’s Rule 10b5‑1 purchases at low price points suggest a long‑term belief in the company’s product pipeline, but the negative earnings and low price‑to‑earnings ratio mean that the stock is still a high‑risk investment. For those weighing a position, Ionel’s buying can be viewed as a confidence indicator, but it should be balanced against the broader fundamentals and the company’s ongoing need to generate positive cash flow from its battery technology initiatives.