Amprius Technologies, Inc.
US ˙ NYSE ˙ US03214Q1085

SecurityAMPX / Amprius Technologies, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership1,438,660 shares
Latest Disclosed Value $ 24,255,808
Citadel Advisors Llc ownership in AMPX / Amprius Technologies, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 1,438,660 shares of Amprius Technologies, Inc. (US:AMPX) valued at $24,255,808 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 454,854 shares of Amprius Technologies, Inc.. This represents a change in shares of 216.29% during the quarter. The current value of the position is $28,327,215 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (AMPX) in the form of stock options. The firm currently holds call options representing 1,443,800 of underlying shares valued at $24,342,468 USD and put options representing 1,334,300 of underlying shares valued at $22,496,298 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

AMPX / Amprius Technologies, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 1,438,660 983,806 216.29 24,256 576.00 0.0039
2026-02-17 2025-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 454,854 -2,051,945 -81.86 3,589 -86.39 0.0005
2025-11-14 2025-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 2,506,799 2,227,142 796.38 26,372 2,140.53 0.0040
2025-08-14 2025-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 279,657 250,250 850.99 1,177 1,408.97 0.0002
2025-05-15 2025-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 29,407 29,407 79 0.0000
2024-11-14 2024-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 0 -105,455 -100.00 0 -100.00
2024-08-14 2024-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 105,455 -23,451 -18.19 134 -61.00 0.0000
2024-05-15 2024-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 128,906 128,906 342 0.0001
2023-02-14 2022-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 0 -12,770 -100.00 0 -100.00
2022-11-14 2022-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK 03214Q108 12,770 12,770 118 0.0000
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 1,443,800 93.46 24,342 313.42 n/a n/a n/a
2026-02-17 2025-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 746,300 5.84 5,888 -20.61 n/a n/a n/a
2025-11-14 2025-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 705,100 1,967.74 7,418 5,086.71 n/a n/a n/a
2025-08-14 2025-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 34,100 -44.19 144 -12.27 n/a n/a n/a
2025-05-15 2025-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 61,100 38.24 164 32.52 n/a n/a n/a
2025-02-14 2024-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 44,200 237.40 124 778.57 n/a n/a n/a
2024-11-14 2024-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 13,100 87.14 15 75.00 n/a n/a n/a
2024-08-14 2024-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 7,000 -89.60 9 -95.51 n/a n/a n/a
2024-05-15 2024-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 67,300 -8.81 178 -54.36 n/a n/a n/a
2024-02-14 2023-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 73,800 4.98 390 17.12 n/a n/a n/a
2023-11-14 2023-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 70,300 333 n/a n/a n/a
2023-08-14 2023-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-05-15 2023-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 159,600 1.14 1,390 11.11 n/a n/a n/a
2023-02-14 2022-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Call 157,800 1,251 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 1,334,300 164.06 22,496 464.38 n/a n/a n/a
2026-02-17 2025-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 505,300 102.12 3,987 51.56 n/a n/a n/a
2025-11-14 2025-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 250,000 1,624.14 2,630 4,211.48 n/a n/a n/a
2025-08-14 2025-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 14,500 -35.56 61 1.67 n/a n/a n/a
2025-05-15 2025-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 22,500 -2.60 60 -6.25 n/a n/a n/a
2025-02-14 2024-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 23,100 225.35 65 814.29 n/a n/a n/a
2024-11-14 2024-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 7,100 36.54 8 16.67 n/a n/a n/a
2024-08-14 2024-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 5,200 -78.06 7 -90.32 n/a n/a n/a
2024-05-15 2024-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 23,700 451.16 63 181.82 n/a n/a n/a
2024-02-14 2023-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 4,300 -66.92 23 -63.93 n/a n/a n/a
2023-11-14 2023-09-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 13,000 62 n/a n/a n/a
2023-08-14 2023-06-30 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-05-15 2023-03-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 7,300 508.33 64 600.00 n/a n/a n/a
2023-02-14 2022-12-31 13F AMPRIUS TECHNOLOGIES COMMON STOCK Put 1,200 10 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.