Axcelis Technologies, Inc.
US ˙ NasdaqGS ˙ US0545402085

SecurityACLS / Axcelis Technologies, Inc.
InstitutionBoston Partners
Latest Disclosed Ownership340,275 shares
Latest Disclosed Value $ 31,791,257
Boston Partners reports 19.45% decrease in ownership of ACLS / Axcelis Technologies, Inc.

On May 11, 2026 - Boston Partners filed a 13F-HR form disclosing ownership of 340,275 shares of Axcelis Technologies, Inc. (US:ACLS) valued at $31,672,797 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 422,435 shares of Axcelis Technologies, Inc.. This represents a change in shares of -19.45% during the quarter. The current value of the position is $54,168,377 USD.

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.

Upgrade to unlock premium data and export to Excel .

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)
2026-05-11 2026-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 340,275 -82,160 -19.45 31,791 -9.34 0.0142
2026-02-13 2025-12-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 422,435 -46,306 -9.88 35,066 -21.91 0.0363
2025-11-13 2025-09-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 468,741 -5,302 -1.12 44,903 33.58 0.0461
2025-08-12 2025-06-30 13F/A-1 AXCELIS TECHNOLOGIES COM NEW 054540208 474,043 141,004 42.34 33,616 106.06 0.0373
2025-08-07 2025-06-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 474,043 141,004 33,616 0.0154
2025-05-13 2025-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 333,039 2,966 0.90 16,313 -29.37 0.0197
2025-02-11 2024-12-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 330,073 84,481 34.40 23,095 -8.48 0.0281
2024-11-12 2024-09-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 245,592 81 0.03 25,237 -25.16 0.0298
2024-08-14 2024-06-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 245,511 53,251 27.70 33,721 61.97 0.0419
2024-05-28 2024-03-31 13F/A-1 AXCELIS TECHNOLOGIES COM NEW 054540208 192,260 192,260 20,819 0.0248
2024-05-13 2024-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 192,260 192,260 20,819 0.0103
2023-05-09 2023-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 0 -16,045 -100.00 0 -100.00
2023-02-08 2022-12-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 16,045 4,569 39.81 1,273 83.17 0.0017
2022-11-09 2022-09-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 11,476 2,061 21.89 695 34.69 0.0010
2022-08-10 2022-06-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 9,415 2,428 34.75 516 -2.27 0.0007
2022-05-10 2022-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 6,987 -7,852 -52.91 528 -52.26 0.0006
2022-02-04 2021-12-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 14,839 -47,450 -76.18 1,106 -62.24 0.0013
2021-11-05 2021-09-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 62,289 -18,451 -22.85 2,929 -10.26 0.0037
2021-08-12 2021-06-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 80,740 -48,127 -37.35 3,264 -38.36 0.0042
2021-05-10 2021-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 128,867 33,716 35.43 5,295 91.16 0.0071
2021-02-10 2020-12-31 13F/A-1 AXCELIS TECHNOLOGIES COM NEW 054540208 95,151 7,090 8.05 2,770 42.93 0.0043
2021-02-04 2020-12-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 95,151 7,090 2,770 1,661.8354
2020-11-13 2020-09-30 13F/A-1 AXCELIS TECHNOLOGIES COM NEW 054540208 88,061 -22,852 -20.60 1,938 -37.26 0.0035
2020-11-09 2020-09-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 110,913 0 3,089 2,267.6940
2020-08-12 2020-06-30 13F AXCELIS TECHNOLOGIES COM NEW 054540208 110,913 1,591 1.46 3,089 54.37 0.0057
2020-05-13 2020-03-31 13F AXCELIS TECHNOLOGIES COM NEW 054540208 109,322 109,322 2,001 0.0040
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.