Axcelis Technologies, Inc.
MX ˙ BMV ˙ US0545402085
SecurityMX:ACLS / Axcelis Technologies, Inc.
InstitutionPenbrook Management LLC
Latest Disclosed Ownership12,095 shares
Latest Disclosed Value $ 1,125,802
Penbrook Management LLC ownership in ACLS / Axcelis Technologies, Inc.

On April 21, 2026 - Penbrook Management LLC filed a 13F-HR form disclosing ownership of 12,095 shares of Axcelis Technologies, Inc. (MX:ACLS) valued at $1,125,802 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 6, 2026 disclosing 15,895 shares of Axcelis Technologies, Inc.. This represents a change in shares of -23.91% during the quarter.

Penbrook Management LLC has a history of taking positions in derivatives of the underlying security (ACLS) in the form of stock options.

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.

MX:ACLS / Axcelis 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)
2026-04-21 2026-03-31 13F AXCELIS TECHNOLOGIES INC COM Stock 054540208 12,095 -3,800 -23.91 1,126 -11.90 0.8525
2026-01-06 2025-12-31 13F AXCELIS TECHNOLOGIES INC COM Stock 054540208 15,895 -1,000 -5.92 1,277 -22.56 0.8808
2025-10-22 2025-09-30 13F AXCELIS TECHNOLOGIES INC COM Stock 054540208 16,895 0 0.00 1,650 40.10 1.1518
2025-07-28 2025-06-30 13F/A-1 AXCELIS TECHNOLOGIES INC COM Stock 054540208 16,895 -2,745 -13.98 1,177 20.72 0.8854
2025-07-25 2025-06-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 19,640 0 976 0.7374
2025-04-01 2025-03-31 13F AXCELIS TECHNOLOGIES INC Stock 054540208 19,640 75 0.38 976 -28.68 0.7374
2025-01-23 2024-12-31 13F AXCELIS TECHNOLOGIES INC Stock 054540208 19,565 0 0.00 1,367 -33.35 0.9325
2024-10-15 2024-09-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 19,565 -3,360 -14.66 2,051 -37.07 1.3336
2024-07-24 2024-06-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 22,925 -19,535 -46.01 3,260 -31.17 1.9897
2024-04-18 2024-03-31 13F AXCELIS TECHNOLOGIES INC Stock 054540208 42,460 -580 -1.35 4,735 -15.16 2.9348
2024-01-16 2023-12-31 13F AXCELIS TECHNOLOGIES Stock 054540208 43,040 -550 -1.26 5,582 -21.47 3.7502
2023-10-10 2023-09-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 43,590 -1,035 -2.32 7,107 -13.13 5.2080
2023-07-17 2023-06-30 13F AXCELIS TECHNOLOGIES Stock 054540208 44,625 -2,685 -5.68 8,181 29.77 5.9296
2023-04-20 2023-03-31 13F AXCELIS TECHNOLOGIES Stock 054540208 47,310 -365 -0.77 6,304 66.64 4.8303
2023-01-24 2022-12-31 13F AXCELIS TECHNOLOGIES INC Stock 054540208 47,675 0 0.00 3,783 31.04 3.2247
2022-10-31 2022-09-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 47,675 -250 -0.52 2,887 9.86 2.4846
2022-07-29 2022-06-30 13F AXCELIS TECHNOLOGIES INC Stock 054540208 47,925 -225 -0.47 2,628 -27.74 2.0725
2022-04-26 2022-03-31 13F AXCELIS TECHNOLOGIES INC COM Stock 054540208 48,150 -14,150 -22.71 3,637 -21.70 2.3594
2022-01-10 2021-12-31 13F AXCELIS TECHNOLOGIES Stock 054540208 62,300 -1,500 -2.35 4,645 54.78 2.7988
2021-10-26 2021-09-30 13F AXCELIS TECHNOLOGIES INC COM Stock 054540208 63,800 -750 -1.16 3,001 15.02 1.8649
2021-07-27 2021-06-30 13F AXCELIS TECHNOLOGIES INC COM COM 054540208 64,550 -1,250 -1.90 2,609 -3.51 1.5638
2021-05-06 2021-03-31 13F/A-2 AXCELIS TECHNOLOGIES INC Stock 054540208 65,800 -5,950 -8.29 2,704 29.44 1.9460
2021-05-05 2021-03-31 13F/A-1 AXCELIS TECHNOLOGIES INC Stock 054540208 65,800 0 2,704 1.9615
2021-04-16 2021-03-31 13F AXCELIS TECHNOLOGIES Stock 054540208 81,325 9,575 1,489 1.7336
2022-04-25 2020-12-31 13F/A-1 AXCELIS TECHNOLOGIES INC COM Stock 054540208 71,750 0 0.00 2,089 32.30 1.6091
2021-01-27 2020-12-31 13F AXCELIS TECHNOLOGIES INC COM 054540208 71,750 0 2,089 1.4727
2020-10-23 2020-09-30 13F AXCELIS TECHNOLOGIES COM 054540208 71,750 150 0.21 1,579 -20.81 1.3688
2020-07-28 2020-06-30 13F AXCELIS TECHNOLOGIES INC COM N COM 054540208 71,600 -9,000 -11.17 1,994 35.19 1.9614
2020-04-14 2020-03-31 13F AXCELIS TECHNOLOGIES COM 054540208 80,600 -5,925 -6.85 1,475 -29.26 1.8888
2020-01-16 2019-12-31 13F AXCELIS TECHNOLOGIES COM 054540208 86,525 -300 -0.35 2,085 40.50 2.0316
2019-10-11 2019-09-30 13F AXCELIS TECHNOLOGIES COM 054540208 86,825 -700 -0.80 1,484 12.68 1.6102
2019-07-15 2019-06-30 13F AXCELIS TECHNOLOGIES COM 054540208 87,525 0 0.00 1,317 -25.21 1.4130
2019-04-24 2019-03-31 13F AXCELIS TECHNOLOGIES COM 054540208 87,525 -4,675 -5.07 1,761 7.31 1.8311
2019-02-01 2018-12-31 13F AXCELIS TECHNOLOGIES COM 054540208 92,200 0 0.00 1,641 -9.39 1.8727
2018-10-23 2018-09-30 13F AXCELIS TECHNOLOGIES COM 054540208 92,200 -350 -0.38 1,811 -1.15 1.7346
2018-07-30 2018-06-30 13F AXCELIS TECHNOLOGIES COM 054540208 92,550 0 0.00 1,832 -19.54 1.7622
2018-04-27 2018-03-31 13F AXCELIS TECHNOLOGIES COM 054540208 92,550 -4,255 -4.40 2,277 -18.03 2.2767
2018-02-21 2017-12-31 13F AXCELIS TECHNOLOGIES COM 054540208 96,805 -25,555 -20.89 2,778 70.95 2.5011
2016-10-27 2016-09-30 13F AXCELIS TECHNOLOGIES COM 054540208 122,360 -367,080 -75.00 1,625 23.39 1.7510
2016-08-05 2016-06-30 13F AXCELIS TECHNOLOGIES COM 054540208 489,440 -2,000 -0.41 1,317 -4.29 1.4521
2016-04-21 2016-03-31 13F AXCELIS TECHNOLOGIES COM 054540109 491,440 -23,000 -4.47 1,376 3.30 1.5150
2016-01-29 2015-12-31 13F AXCELIS TECHNOLOGIES COM 054540109 514,440 -6,900 -1.32 1,332 -4.31 1.3661
2015-11-12 2015-09-30 13F AXCELIS TECHNOLOGIES COM 054540109 521,340 -7,320 -1.38 1,392 -11.05 1.4740
2015-08-04 2015-06-30 13F AXCELIS TECHNOLOGIES INC COM COM 054540109 528,660 -720 -0.14 1,565 24.21 1.4862
2015-04-27 2015-03-31 13F AXCELIS TECHNOLOGIES COM 054540109 529,380 529,380 0.14 1,260 -19.49 1.1192
2015-01-28 2014-12-31 13F AXCELIS TECHNOLOGIES COM 054540109 0 -531,100 -100.00 0 -100.00
2014-10-16 2014-09-30 13F AXCELIS TECHNOLOGIES COM 054540109 531,100 0 0.00 1,057 -0.47 0.9746
2014-08-04 2014-06-30 13F AXCELIS TECHNOLOGIES COM 054540109 531,100 14,400 2.79 1,062 -4.41 0.9379
2014-05-07 2014-03-31 13F/A-1 AXCELIS TECHNOLOGIES COM 054540109 516,700 -4,600 -0.88 1,111 -12.66 1.0506
2014-05-02 2014-03-31 13F AXCELIS TECHNOLOGIES COM 054540109 521,300 1,272
2014-03-25 2013-12-31 13F AXCELIS TECHNOLOGIES COM 054540109 521,300 521,300 1,272 1.2343
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
(%)
2024-01-16 2023-12-31 13F AXCELIS TECHNOLOGIES Opt Put 0 -100.00 0 n/a n/a n/a
2023-10-10 2023-09-30 13F AXCELIS TECHNOLOGIES Opt Put 4,000 0.00 1 n/a n/a n/a
2023-07-17 2023-06-30 13F AXCELIS TECHNOLOGIES Opt Put 4,000 1 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.