ACM Research, Inc.
US ˙ NasdaqGM ˙ US00108J1097

SecurityACMR / ACM Research, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership24,464 shares
Latest Disclosed Value $ 962,658
Simplex Trading, Llc ownership in ACMR / ACM Research, Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 24,464 shares of ACM Research, Inc. (US:ACMR) valued at $962,658 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 110,952 shares of ACM Research, Inc.. This represents a change in shares of -77.95% during the quarter. The current value of the position is $2,173,871 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (ACMR) in the form of stock options. The firm currently holds call options representing 17,900 of underlying shares valued at $704,365 USD and put options representing 26,100 of underlying shares valued at $1,027,035 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.

ACMR / ACM Research, 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)
2026-05-14 2026-03-31 13F ACM RESH COM 00108J109 24,464 -86,488 -77.95 963 -78.02 0.0003
2026-02-11 2025-12-31 13F ACM RESH COM 00108J109 110,952 35,934 47.90 4,377 218,750.00 0.0025
2025-11-12 2025-09-30 13F ACM RESH COM 00108J109 75,018 -20,692 -21.62 3 0.00 0.0015
2025-08-05 2025-06-30 13F ACM RESH COM 00108J109 95,710 -14,418 -13.09 2 0.00 0.0014
2025-05-12 2025-03-31 13F ACM RESH COM 00108J109 110,128 -31,308 -22.14 3 0.00 0.0016
2025-02-11 2024-12-31 13F ACM RESH COM 00108J109 141,436 106,610 306.12 2 0.0012
2024-11-08 2024-09-30 13F ACM RESH COM 00108J109 34,826 -15,439 -30.72 1 -100.00 0.0004
2024-07-25 2024-06-30 13F ACM RESH COM 00108J109 50,265 50,265 1 0.0007
2024-04-25 2024-03-31 13F ACM RESH COM 00108J109 0 -67,124 -100.00 0 -100.00
2024-02-02 2023-12-31 13F ACM RESH COM 00108J109 67,124 67,124 1 0.0008
2023-08-04 2023-06-30 13F ACM RESH COM 00108J109 0 -57,465 -100.00 0 0.0000
2023-04-27 2023-03-31 13F ACM RESH COM 00108J109 57,465 50,003 670.10 1 0.0006
2023-02-02 2022-12-31 13F ACM RESH COM 00108J109 7,462 -28,253 -79.11 0 -100.00 0.0001
2022-11-04 2022-09-30 13F ACM RESH COM 00108J109 35,715 22,357 167.37 445 98.66 0.0005
2022-08-03 2022-06-30 13F ACM RESH COM 00108J109 13,358 -68,283 -83.64 224 -86.74 0.0002
2022-05-02 2022-03-31 13F ACM RESH COM 00108J109 81,641 80,286 5,925.17 1,689 1,368.70 0.0015
2022-02-23 2021-12-31 13F/A-1 ACM RESH COM 00108J109 1,355 1,355 115 0.0001
2021-08-12 2021-06-30 13F ACM RESEARCH COM 00108J109 0 -10,480 -100.00 0 -100.00
2021-04-26 2021-03-31 13F ACM RESEARCH COM 00108J109 10,480 10,480 846 0.0015
2021-02-02 2020-12-31 13F ACM RESEARCH COM 00108J109 0 -30,103 -100.00 0 -100.00
2020-10-14 2020-09-30 13F ACM RESEARCH COM 00108J109 30,103 25,354 533.88 2,080 602.70 0.0028
2020-07-13 2020-06-30 13F ACM RESEARCH COM 00108J109 4,749 -329 -6.48 296 97.33 0.0005
2020-04-29 2020-03-31 13F ACM RESEARCH COM 00108J109 5,078 5,078 150 0.0003
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
(%)
2026-05-14 2026-03-31 13F ACM RESH CALL Call 17,900 -58.08 704 -58.19 n/a n/a n/a
2026-02-11 2025-12-31 13F ACM RESH CALL Call 42,700 -77.74 1,685 23,957.14 n/a n/a n/a
2025-11-12 2025-09-30 13F ACM RESH CALL Call 191,800 547.97 8 n/a n/a n/a
2025-08-05 2025-06-30 13F ACM RESH CALL Call 29,600 -47.70 1 -100.00 n/a n/a n/a
2025-05-12 2025-03-31 13F ACM RESH CALL Call 56,600 -3.58 1 n/a n/a n/a
2025-02-11 2024-12-31 13F ACM RESH CALL Call 58,700 -55.19 1 -100.00 n/a n/a n/a
2024-11-08 2024-09-30 13F ACM RESH CALL Call 131,000 6.76 3 0.00 n/a n/a n/a
2024-07-25 2024-06-30 13F ACM RESH CALL Call 122,700 -45.42 3 -66.67 n/a n/a n/a
2024-04-25 2024-03-31 13F ACM RESH CALL Call 224,800 57.87 7 200.00 n/a n/a n/a
2024-02-02 2023-12-31 13F ACM RESH CALL Call 142,400 -37.87 3 -50.00 n/a n/a n/a
2023-11-01 2023-09-30 13F ACM RESH CALL Call 229,200 124.93 4 300.00 n/a n/a n/a
2023-08-04 2023-06-30 13F ACM RESH CALL Call 101,900 75.99 1 n/a n/a n/a
2023-04-27 2023-03-31 13F ACM RESH CALL Call 57,900 849.18 1 n/a n/a n/a
2023-02-02 2022-12-31 13F ACM RESH CALL Call 6,100 -60.90 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ACM RESH CALL Call 15,600 -8.24 194 -32.17 n/a n/a n/a
2022-08-03 2022-06-30 13F ACM RESH CALL Call 17,000 -50.87 286 -60.00 n/a n/a n/a
2022-05-02 2022-03-31 13F ACM RESH CALL Call 34,600 1,630.00 715 320.59 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ACM RESH CALL Call 2,000 -95.12 170 -95.93 n/a n/a n/a
2022-02-04 2021-12-31 13F ACM RESH CALL Call 41,000 4,177 n/a n/a n/a
2021-10-28 2021-09-30 13F ACM RESH CALL Call 41,000 0.00 4,177 -0.33 n/a n/a n/a
2021-08-12 2021-06-30 13F ACM RESH CALL Call 41,000 128,025.00 4,191 1,524.42 n/a n/a n/a
2021-04-26 2021-03-31 13F ACM RESEARCH CALL Call 32 -17.95 258 -18.35 n/a n/a n/a
2021-02-02 2020-12-31 13F ACM RESEARCH CALL Call 39 25.81 316 47.66 n/a n/a n/a
2020-10-14 2020-09-30 13F ACM RESEARCH CALL Call 31 -27.91 214 -20.15 n/a n/a n/a
2020-07-13 2020-06-30 13F ACM RESEARCH CALL Call 43 -2.27 268 106.15 n/a n/a n/a
2020-04-29 2020-03-31 13F ACM RESEARCH CALL Call 44 130 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
(%)
2026-05-14 2026-03-31 13F ACM RESH PUT Put 26,100 -77.21 1,027 -77.26 n/a n/a n/a
2026-02-11 2025-12-31 13F ACM RESH PUT Put 114,500 -7.51 4,517 112,825.00 n/a n/a n/a
2025-11-12 2025-09-30 13F ACM RESH PUT Put 123,800 -24.56 5 0.00 n/a n/a n/a
2025-08-05 2025-06-30 13F ACM RESH PUT Put 164,100 -22.89 4 0.00 n/a n/a n/a
2025-05-12 2025-03-31 13F ACM RESH PUT Put 212,800 -22.28 5 0.00 n/a n/a n/a
2025-02-11 2024-12-31 13F ACM RESH PUT Put 273,800 476.42 4 n/a n/a n/a
2024-11-08 2024-09-30 13F ACM RESH PUT Put 47,500 -69.76 1 -100.00 n/a n/a n/a
2024-07-25 2024-06-30 13F ACM RESH PUT Put 157,100 132.40 4 200.00 n/a n/a n/a
2024-04-25 2024-03-31 13F ACM RESH PUT Put 67,600 -38.38 2 -50.00 n/a n/a n/a
2024-02-02 2023-12-31 13F ACM RESH PUT Put 109,700 43.96 2 100.00 n/a n/a n/a
2023-11-01 2023-09-30 13F ACM RESH PUT Put 76,200 323.33 1 n/a n/a n/a
2023-08-04 2023-06-30 13F ACM RESH PUT Put 18,000 -71.11 0 n/a n/a n/a
2023-04-27 2023-03-31 13F ACM RESH PUT Put 62,300 461.26 1 n/a n/a n/a
2023-02-02 2022-12-31 13F ACM RESH PUT Put 11,100 484.21 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ACM RESH PUT Put 1,900 -90.64 23 -93.26 n/a n/a n/a
2022-08-03 2022-06-30 13F ACM RESH PUT Put 20,300 -85.59 341 -88.30 n/a n/a n/a
2022-05-02 2022-03-31 13F ACM RESH PUT Put 140,900 2,509.26 2,915 533.70 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ACM RESH PUT Put 5,400 58.82 460 32.95 n/a n/a n/a
2022-02-04 2021-12-31 13F ACM RESH PUT Put 3,400 346 n/a n/a n/a
2021-10-28 2021-09-30 13F ACM RESH PUT Put 3,400 0.00 346 -0.29 n/a n/a n/a
2021-08-12 2021-06-30 13F ACM RESH PUT Put 3,400 591.06 347 -91.27 n/a n/a n/a
2021-04-26 2021-03-31 13F ACM RESEARCH PUT Put 492 1,018.18 3,974 1,013.17 n/a n/a n/a
2021-02-02 2020-12-31 13F ACM RESEARCH PUT Put 44 -95.98 357 -95.28 n/a n/a n/a
2020-10-14 2020-09-30 13F ACM RESEARCH PUT Put 1,095 -10.54 7,566 -0.86 n/a n/a n/a
2020-07-13 2020-06-30 13F ACM RESEARCH PUT Put 1,224 337.14 7,632 820.63 n/a n/a n/a
2020-04-29 2020-03-31 13F ACM RESEARCH PUT Put 280 829 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.