Amprius Technologies, Inc. filings document operating results, material events, governance matters and capital-structure disclosures for a public battery technology company. Its 8-K reports include quarterly and annual financial-result releases, material agreement updates, auditor changes, lease-related matters, and equity offering activity.
Amprius disclosure records also cover proxy and shareholder voting matters, emerging growth company status, common stock, redeemable warrants, and board and executive compensation topics. These filings provide the formal record for the company's silicon-anode battery business, security structure, financing activity, risk disclosures and corporate governance practices.
Stefan Constantin Ionel reported acquisition or exercise transactions in this Form 4 filing.
Amprius Technologies, Inc. Chief Technology Officer Stefan Constantin Ionel reported an award of 110,000 shares of common stock in the form of restricted stock units at a price of $0.0000 per share. These RSUs vest 1/16 on May 20, 2026 and then quarterly on August 20, November 20, February 20 and May 20 until fully vested on February 20, 2030. Following this award, he directly holds 833,330 shares/units in total, including 643,440 restricted stock units subject to their respective vesting conditions.
Amprius Technologies, Inc. provides an overview of its silicon-anode lithium-ion battery business, focusing on high‑energy, fast‑charging cells for aviation, drones, HAPS, eVTOL and light electric vehicles. The company highlights over 500 customer engagements and more than 4.2 million battery cells shipped through December 31, 2025.
Amprius now relies heavily on its SiCore platform, produced via global contract manufacturers with access to over 2.0 GWh of annual capacity, while its Fremont facility is being expanded to a 10 MWh SiCore pilot line under a $14.8 million DIU contract. It recorded $19.1 million in impairment charges tied to terminating a large Brighton, Colorado factory lease and agreed to end that lease for a one‑time $20.0 million payment. The report also stresses concentration risk, noting one customer generated $27.1 million of 2025 revenue, and details extensive technology IP, regulatory exposure, and comprehensive risk factors.
Amprius Technologies reported very strong growth for 2025, with revenue rising 202% to $73.0 million and fourth-quarter revenue up 137% year over year to $25.2 million. Q4 gross margin improved to 24%, supporting the company’s first positive quarterly non-GAAP adjusted EBITDA of $1.8 million.
Full-year net loss was $44.0 million, including a $22.5 million impairment tied to a terminated Colorado facility; excluding this, adjusted net loss was $21.5 million and adjusted EBITDA was $(5.3) million. Management expects at least $125.0 million of revenue in 2026, net loss under $8.0 million, and at least $4.0 million of positive adjusted EBITDA, reflecting confidence in its contract manufacturing model and growing defense and aerospace demand.
Amprius Technologies director Sun Kang sold 61,251 shares of common stock on February 23, 2026 at an average price of $10.1555. According to the filing, this was a non-discretionary, sell-to-cover transaction mandated by the company to fund tax withholding on vesting restricted stock units.
After this sale, Kang directly holds 1,342,400 shares of Amprius common stock, which includes 1,159,385 restricted stock units. He also has indirect ownership of 274,275 shares through the KANG & CECILLIA SUN FAMILY REVOCABLE TRUST, where he and his spouse serve as co-trustees.
Amprius Technologies Chief Technology Officer Stefan Constantin Ionel reported an open-market sale of 25,366 shares of common stock at an average price of $10.1555 per share. The sale was made under a non-discretionary, issuer-mandated sell-to-cover arrangement for tax withholding on vesting restricted stock units. After the transaction, he holds 723,330 shares, including 533,440 restricted stock units that may convert into common stock as they vest.
AMPX submitted a Form 144 notice disclosing proposed and completed transactions in its common stock. The filing records a release of restricted stock units of 126,191 shares on 02/20/2026. The excerpt also lists 10b5-1 sales attributed to KANG SUN: 506,267 shares on 01/12/2026 for $5,111,474.14, 950,548 shares on 01/16/2026 for $10,518,669.11, and 43,185 shares on 01/20/2026 for $476,274.41.
AMPX insider transactions: Stefan Constantin Ionel reported multiple 10b5-1 sales of AMPX common stock on 12/11/2025, 01/21/2026, 01/22/2026, 01/23/2026, 01/28/2026, and 01/22/2026 (see amounts below). The filing also records a release of restricted stock units of 52,257 shares on 02/20/2026 labeled as Compensation.
Representative 10b5-1 sales shown include 125,000 shares on 12/11/2025 (proceeds 1313575) and 492,827 shares on 01/22/2026 (proceeds 5931912.19). Broker listed: Morgan Stanley Smith Barney LLC.
Amprius Technologies has terminated its lease for approximately 774,155 rentable square feet at a Colorado property in Brighton. The lease termination agreement with Starboard Platform Brighton JV, LLC became effective on January 31, 2026, releasing both parties from most future obligations under the lease.
To end the 15-year lease, which began in June 2024, Amprius paid a $20,000,000 termination fee. The landlord will return the company’s security deposit, currently held as a $1,200,000 letter of credit, on or before February 5, 2026. The company’s base rent for the Colorado property was approximately $300,000, plus about $190,000 in additional rent for operating expenses, insurance, and real estate taxes, with base rent subject to annual increases of about 3.3%.
Amprius Technologies, Inc. Chief Technology Officer Stefan Constantin Ionel reported option exercises and a related share sale. On January 28, 2026, he exercised stock options for 90 shares at $0.62 and 39,600 shares at $0.05, receiving the same number of common shares.
That same day, he sold 39,690 common shares at an average price of $12.0018, with individual trades ranging from $12.00 to $12.02. After these transactions, he directly beneficially owned 748,696 common shares, including 585,697 restricted stock units. All exercises and sales were made under a Rule 10b5-1 trading plan adopted on September 11, 2025.
Amprius Technologies Chief Technology Officer Stefan Constantin Ionel reported a series of stock option exercises and share sales in January 2026. Between January 21 and 23, 2026, he exercised multiple stock options with exercise prices ranging from $0.05 to $0.62 per share, converting them into common stock.
On those same dates he sold several blocks of common stock, including 73,280 shares at an average price of $12.0007, 492,827 shares at an average price of $12.0365, and 1,600 shares at $12.00, all under a Rule 10b5-1 trading plan adopted on September 11, 2025. Following these transactions, he directly owned 748,696 shares of common stock, which includes 585,697 restricted stock units that may settle into shares if their vesting conditions are met.