HolderBook

AMPRIUS TECHNOLOGIES INC (AMPX)

Institutional ownership reported to the SEC as of Q3 2026, across 17 quarters.

9
Reporting holders
$645.1K
Reported value
0.0%
Calls
0.0%
Puts
-258
Holder change

Calls and puts are the parts of reported value carried in derivative lines rather than shares, and they point in opposite directions: a manager holding calls is positioned for the security, one holding puts against it - or hedging shares they already own, which is why index funds carry so many. Most sites add the two together and report one figure, which averages away the only interesting part.

Holders

Download these holders as CSV

FilerValueShares Their book Held Change
ZEVENBERGEN CAPITAL INVESTMENTS LLC$503.8K52,0500.01%3q-86.4%-$3.2M
Central Pacific Bank - Trust Division$67.8K6,9990.01%3qHELD
Bank of New Hampshire$26.6K2,7450.01%3qHELD
EASTERN BANK$19.4K2,0000.00%9qHELD
GAMMA Investing LLC$18.3K1,8920.00%5q+117.0%+$9.9K
Farther Finance Advisors, LLC$8.0K8240.00%9q-41.9%-$5.7K
TOTH FINANCIAL ADVISORY CORP$1.0K1060.00%newNEW
CoreCap Advisors, LLC$242250.00%newNEW
Miller Global Investments, LLC$3940.00%2qHELD

Five percent filings

Anyone crossing 5% of a company must say so within days - far sooner than the next quarterly holdings report. A 13D declares an intent to influence the company; a 13G is the passive version. See all activist filings →

FiledFormFiler % of class
2026-08-1013G/AJANE STREET GROUP, LLCwith 2 co-filers3.3%
2026-07-2713G/ABlackRock, Inc.7.4%

What the company announced

Form 8-K filings from the last 120 days, showing only the items worth a reader's attention. Earnings releases, exhibit attachments and general disclosures are filed constantly and are left out. Filed is when the SEC received it; event is the date the company says the thing happened.

FiledEvent dateWhatSource
2026-09-282026-09-23Material agreement enteredfiling

What the insiders did

Open market purchases and sales reported on Form 4 in the last 180 days. Grants, option exercises and shares surrendered to cover tax are left out: they are compensation rather than a decision to buy or sell. Where a broker filled one order in tranches the lines are summed, because it was one decision.

Officers and directors

DateInsiderRoleSideSharesValue
2026-06-15DIXON DONALD RDirectorSold85,000$1.5M
2026-05-21Sun KangDirectorSold67,796$1.0M
2026-05-21Stepien Thomas MChief Executive OfficerSold60,702$897.7K
2026-06-09DIXON DONALD RDirectorSold40,000$765.2K
2026-08-21Sun KangDirectorSold62,101$642.2K
2026-05-21Stefan Constantin IonelChief Technology OfficerSold28,812$426.1K
2026-05-26DIXON DONALD RDirectorSold17,895$320.3K
2026-08-21Stefan Constantin IonelChief Technology OfficerSold29,681$306.9K
2026-08-21Stepien Thomas MChief Executive OfficerSold23,529$243.3K

Quarter by quarter

Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.

QuarterHoldersValue SharesNewAdded TrimmedOptions
Q3 20269$645.1K66,6452120.0%
Q2 2026267$1.9B103,678,522661086125.1%
Q1 2026254$1.8B85,043,98179965419.3%
Q4 2025211$613.9M67,880,51845855312.7%
Q3 2025192$752.2M64,532,7569161269.7%
Q2 2025122$171.0M38,086,2943945206.2%
Q1 2025100$61.8M20,903,8782834169.3%
Q4 202495$57.4M16,645,86232291118.8%
Q3 202469$12.4M8,290,12412271326.0%
Q2 202467$14.5M8,756,2912320723.5%
Q1 202449$21.7M5,120,7136131637.4%
Q4 202353$41.3M4,540,698819841.9%
Q3 202349$30.4M4,109,296915835.9%
Q2 202346$33.3M2,710,7222212641.5%
Q1 202334$35.1M1,947,022107551.7%
Q4 202231$29.8M1,860,925233250.4%
Q3 202213$22.2M2,289,35813005.1%