Welcome to our dedicated page for Amprius Tech SEC filings (Ticker: AMPX), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
This page provides access to U.S. SEC filings for Amprius Technologies, Inc. (NYSE: AMPX), a manufacturer of high-energy and high-power lithium-ion batteries based on a Silicon Anode Platform. These regulatory documents offer detailed insight into the company’s operations, capital structure, executive changes, and financing activities.
Amprius uses current reports on Form 8-K to disclose material events. Recent 8-K filings describe the completion of an at-the-market equity offering program established under an At Market Issuance Sales Agreement, including the aggregate offering size and the resulting net proceeds. Other 8-Ks outline leadership transitions, such as the planned change in Chief Executive Officer, the appointment of a new Chief Financial Officer, and related employment and consulting arrangements, including salary, bonus eligibility, equity awards, and severance terms.
Investors and analysts can also use Amprius’ SEC filings to follow its periodic financial reporting. The company has filed 8-Ks to announce quarterly business and financial results and to furnish letters to shareholders discussing results for specific quarters. These filings complement the company’s earnings press releases and conference calls by providing formal disclosure under SEC rules.
On Stock Titan, AI-powered tools summarize lengthy filings so readers can quickly understand the key points in Amprius’ 10-K annual reports, 10-Q quarterly reports, and 8-K current reports, without needing to parse every technical detail. The platform also surfaces information related to equity compensation, executive employment agreements, and capital-raising activities. Real-time updates from EDGAR ensure that new filings, including any future Forms 4 reporting insider transactions, become available promptly with plain-language explanations to help users interpret their significance.
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
Representative 10b5-1 sales shown include 125,000 shares on
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.
Amprius Technologies insider plans sizable stock sale. A Form 144 filing indicates that Stefan Constantin Ionel intends to sell 717,307 shares of AMPX common stock through Morgan Stanley Smith Barney LLC on the NYSE, with an approximate market value of $8,012,319.19. The filing notes that 130,483,838 shares of the company’s common stock are outstanding.
The shares to be sold were acquired on 01/21/2026 through the cash exercise of stock options for the same 717,307-share amount. The form also reports prior sales over the past three months, including 125,000 and 73,255 shares sold on 12/11/2025 for gross proceeds of $1,313,575.00 and $769,807.49, and 25,024 shares sold on 11/21/2025 for $252,274.45. The filing includes a representation that the seller is not aware of undisclosed material adverse information about the issuer’s operations.
Amprius Technologies director Kang Sun reported option exercises and share sales under a pre-arranged trading plan. On January 16, 2026, he exercised stock options for 850,338 shares at
Following these transactions, Sun directly beneficially owned 1,403,651 shares of Amprius common stock, including 1,285,576 restricted stock units, and indirectly held 274,275 shares through the Kang & Cecillia Sun Family Revocable Trust, where he and his spouse are co-trustees. The filing states that the exercises and sales were effected pursuant to a Rule 10b5-1 trading plan adopted on August 18, 2025.