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.
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.
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 $2.5 per share and 100,210 shares at $1.78 per share, then sold 950,548 shares of common stock at an average price of $11.0659 per share. On January 20, 2026, he exercised options for 43,185 shares at $1.78 per share and sold the same number of shares at an average price of $11.0287 per share.
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.
A shareholder filed a Form 144 to sell 1,018,875 common shares on the NYSE, showing an aggregate market value of $10,341,581.25. The shares are to be sold through Morgan Stanley Smith Barney LLC, with an approximate sale date of 01/16/2026, and the filing notes that 130,483,838 shares of the issuer’s stock are outstanding.
The securities to be sold were acquired on 01/16/2026 via the exercise of stock options from the issuer, paid in cash. Over the past three months, the same account reported additional common stock sales, including 1,000,000 shares sold on 11/17/2025 for $10,595,300.00 and 506,267 shares sold on 01/12/2026 for $5,111,474.14, some under a Rule 10b5-1 trading plan.
Amprius Technologies director Sun Kang reported multiple option exercises and a share sale. On January 12, 2026, he exercised three stock option grants for 180,802 shares at $0.62, 208,264 shares at $2.44, and 117,201 shares at $2.50 per share, receiving the same number of common shares in each case. He then sold 506,267 shares of common stock at an average price of $10.0964 under a Rule 10b5-1 trading plan adopted on August 18, 2025.
After these transactions, Sun directly beneficially owned 1,403,651 shares of common stock, which includes 1,285,576 restricted stock units, and held 850,338 stock options directly. In addition, 274,275 shares are held indirectly by the KANG & CECILLIA SUN FAMILY REVOCABLE TRUST, for which he and his spouse serve as co-trustees.
A holder of AMPX common stock has filed a notice of proposed sale under Rule 144 after exercising stock options. The filer plans to sell 506,267 common shares through Morgan Stanley Smith Barney LLC on the NYSE, with an indicated aggregate market value of 4,799,411.16. The approximate sale date is 01/12/2026, and the shares were acquired the same day by cash exercise of stock options from the issuer.
The notice also reports prior sales of the issuer’s common stock during the past three months by the same seller. These include 68,655 shares sold on 11/21/2025 for gross proceeds of 692,131.65, and 1,000,000 shares sold on 11/17/2025 under a Rule 10b5-1 trading plan for gross proceeds of 10,595,300.00. The filing represents that the seller is not aware of undisclosed material adverse information about the issuer.
Amprius Technologies, Inc. reported that it has completed all sales under its at-the-market equity offering program. The program, established under a sales agreement with B. Riley Securities, Cantor Fitzgerald and H.C. Wainwright, authorized offers of common stock up to an aggregate offering price of $100.0 million.
The company issued a total of 25.5 million shares of common stock through this program, generating aggregate net proceeds of approximately $97.5 million. During the three months ended December 31, 2025, Amprius sold additional shares for aggregate net proceeds of about $19.6 million at an average price of $11.17 per share, at which point the program was concluded and the sales agreement terminated in accordance with its terms.