MKS Inc.
US ˙ NasdaqGS ˙ US55306N1046

SecurityMKSI / MKS Inc.
InstitutionAmalgamated Bank
Latest Disclosed Ownership30,869 shares
Latest Disclosed Value $ 7,094
Amalgamated Bank reports 1.35% increase in ownership of MKSI / MKS Inc.

On May 8, 2026 - Amalgamated Bank filed a 13F-HR form disclosing ownership of 30,869 shares of MKS Inc. (US:MKSI) valued at $7,094,005 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 30,459 shares of MKS Inc.. This represents a change in shares of 1.35% during the quarter. The current value of the position is $9,311,634 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.

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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)
2026-05-08 2026-03-31 13F MKS COM 55306N104 30,869 410 1.35 7 75.00 0.0543
2026-02-05 2025-12-31 13F MKS COM 55306N104 30,459 -202 -0.66 5 33.33 0.0351
2025-10-29 2025-09-30 13F MKS COM 55306N104 30,661 41 0.13 4 0.00 0.0271
2025-08-04 2025-06-30 13F MKS COM 55306N104 30,620 -191 -0.62 3 50.00 0.0235
2025-04-25 2025-03-31 13F MKS INSTRUMENTS COM 55306N104 30,811 -1,318 -4.10 2 -33.33 0.0211
2025-02-04 2024-12-31 13F MKS INSTRUMENTS COM 55306N104 32,129 0 0.00 3 0.00 0.0275
2024-10-30 2024-09-30 13F MKS INSTRUMENTS COM 55306N104 32,129 -92 -0.29 3 -25.00 0.0288
2024-08-12 2024-06-30 13F MKS INSTRUMENTS COM 55306N104 32,221 -7,215 -18.30 4 -20.00 0.0358
2024-04-23 2024-03-31 13F MKS INSTRUMENTS COM 55306N104 39,436 -635 -1.58 5 25.00 0.0449
2024-02-06 2023-12-31 13F MKS INSTRUMENTS COM 55306N104 40,071 -428 -1.06 4 33.33 0.0329
2023-11-08 2023-09-30 13F MKS INSTRUMENTS COM 55306N104 40,499 2,347 6.15 4 -25.00 0.0298
2023-08-11 2023-06-30 13F MKS INSTRUMENTS COM 55306N104 38,152 -1,212 -3.08 4 33.33 0.0334
2023-05-02 2023-03-31 13F MKS INSTRUMENTS COM 55306N104 39,364 -8,979 -18.57 3 -25.00 0.0297
2023-02-10 2022-12-31 13F MKS INSTRUMENTS COM 55306N104 48,343 7,414 18.11 4 -99.88 0.0365
2022-11-09 2022-09-30 13F MKS INSTRUMENTS COM 55306N104 40,929 1,944 4.99 3,382 -15.47 0.0326
2022-08-15 2022-06-30 13F MKS INSTRUMENTS COM 55306N104 38,985 -1,945 -4.75 4,001 -34.84 0.0373
2022-08-25 2022-03-31 13F/A-1 MKS INSTRUMENTS COM 55306N104 40,930 -231 -0.56 6,140 -14.35 0.0477
2022-06-30 2022-03-31 13F MKS INSTRUMENTS COM 55306N104 40,930 -231 6,140 0.0488
2022-02-15 2021-12-31 13F/A-1 MKS INSTRUMENTS COM 55306N104 41,161 -464 -1.11 7,169 14.12 0.0529
2022-02-15 2021-12-31 13F MKS INSTRUMENTS COM 55306N104 41,161 -464 7,169 0.0529
2021-10-29 2021-09-30 13F MKS INSTRUMENTS COM 55306N104 41,625 -4,102 -8.97 6,282 -22.80 0.0530
2021-08-16 2021-06-30 13F MKS INSTRUMENTS COM 55306N104 45,727 36,038 371.95 8,137 352.81 0.0652
2021-05-13 2021-03-31 13F MKS INSTRUMENTS COM 55306N104 9,689 -782 -7.47 1,797 14.10 0.0674
2021-02-12 2020-12-31 13F MKS INSTRUMENTS COM 55306N104 10,471 27 0.26 1,575 38.04 0.0597
2020-10-30 2020-09-30 13F MKS INSTRUMENTS COM 55306N104 10,444 -239 -2.24 1,141 -5.70 0.0496
2020-08-10 2020-06-30 13F MKS INSTRUMENTS COM 55306N104 10,683 -1,500 -12.31 1,210 21.98 0.0560
2020-05-13 2020-03-31 13F MKS INSTRUMENTS COM 55306N104 12,183 -221 -1.78 992 -27.33 0.0243
2020-02-13 2019-12-31 13F MKS INSTRUMENTS COM 55306N104 12,404 1,251 11.22 1,365 32.65 0.0251
2019-11-13 2019-09-30 13F MKS INSTRUMENTS COM 55306N104 11,153 -187 -1.65 1,029 16.53 0.0216
2019-08-14 2019-06-30 13F MKS INSTRUMENTS COM 55306N104 11,340 -1,433 -11.22 883 -25.74 0.0206
2019-05-15 2019-03-31 13F MKS INSTRUMENTS COM 55306N104 12,773 176 1.40 1,189 46.07 0.0288
2019-02-15 2018-12-31 13F MKS INSTRUMENTS COM 55306N104 12,597 4,617 57.86 814 27.19 0.0231
2018-11-14 2018-09-30 13F MKS INSTRUMENTS COM 55306N104 7,980 -5,211 -39.50 640 -49.29 0.0158
2018-07-18 2018-06-30 13F MKS INSTRUMENTS COM 55306N104 13,191 5,437 70.12 1,262 40.69 0.0308
2018-05-22 2018-03-31 13F MKS INSTRUMENTS COM 55306N104 7,754 -129 -1.64 897 20.40 0.0238
2018-02-13 2017-12-31 13F MKS INSTRUMENTS COM 55306N104 7,883 462 6.23 745 6.28 0.0202
2017-11-09 2017-09-30 13F MKS INSTRUMENTS COM 55306N104 7,421 -25 -0.34 701 39.92 0.0218
2017-08-10 2017-06-30 13F MKS INSTRUMENTS COM 55306N104 7,446 244 3.39 501 1.21 0.0164
2017-05-12 2017-03-31 13F MKS INSTRUMENTS COM 55306N104 7,202 5 0.07 495 15.65 0.0246
2017-02-14 2016-12-31 13F MKS INSTRUMENTS COM 55306N104 7,197 859 13.55 428 35.87 0.0193
2016-11-15 2016-09-30 13F/A-1 MKS INSTRUMENTS COM 55306N104 6,338 13 0.21 315 6.78 0.0183
2016-08-16 2016-06-30 13F MKS INSTRUMENTS COM 55306N104 6,325 595 10.38 295 36.57 0.0171
2016-05-11 2016-03-31 13F MKS INSTRUMENTS COM 55306N104 5,730 5,730 0.00 216 0.0210
2015-11-04 2015-09-30 13F MKS INSTRUMENTS COM 55306N104 0 -5,508 -100.00 0 -100.00
2015-07-10 2015-06-30 13F MKS INSTRUMENTS COM 55306N104 5,508 5,508 209 0.0205
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.