MKS Inc.
US ˙ NasdaqGS ˙ US55306N1046

SecurityMKSI / MKS Inc.
InstitutionNatixis Advisors, L.p.
Latest Disclosed Ownership232,006 shares
Latest Disclosed Value $ 53,317
Natixis Advisors, L.p. reports 55.59% decrease in ownership of MKSI / MKS Inc.

On May 13, 2026 - Natixis Advisors, L.p. filed a 13F-HR form disclosing ownership of 232,006 shares of MKS Inc. (US:MKSI) valued at $53,317,299 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 522,415 shares of MKS Inc.. This represents a change in shares of -55.59% during the quarter. The current value of the position is $69,984,610 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)
2026-05-13 2026-03-31 13F MKS COM 55306N104 232,006 -290,409 -55.59 53 -36.14 0.0742
2026-02-10 2025-12-31 13F MKS COM 55306N104 522,415 41,247 8.57 83 40.68 0.1183
2025-11-13 2025-09-30 13F MKS INC. COM 55306N104 481,168 -93,009 -16.20 60 3.51 0.0869
2025-08-13 2025-06-30 13F MKS COM 55306N104 574,177 310,053 117.39 57 171.43 0.0905
2025-05-08 2025-03-31 13F MKS INSTRS COM 55306N104 264,124 -19,119 -6.75 21 -27.59 0.0391
2025-02-10 2024-12-31 13F MKS INSTRS COM 55306N104 283,243 191,561 208.94 30 222.22 0.0552
2024-11-06 2024-09-30 13F MKS INSTRS COM 55306N104 91,682 -156,013 -62.99 10 -71.87 0.0194
2024-08-01 2024-06-30 13F MKS INSTRS COM 55306N104 247,695 174,675 239.22 32 255.56 0.0703
2024-04-25 2024-03-31 13F MKS INSTRS COM 55306N104 73,020 73,020 10 0.0223
2024-02-06 2023-12-31 13F M K S INSTRUMENTS COM 55306N104 0 -68,048 -100.00 0 -100.00
2023-11-13 2023-09-30 13F M K S INSTRUMENTS COM 55306N104 68,048 -653 -0.95 6 -28.57 0.0180
2023-08-15 2023-06-30 13F M K S INSTRUMENTS COM 55306N104 68,701 2,578 3.90 7 40.00 0.0229
2023-05-11 2023-03-31 13F M K S INSTRUMENTS COM 55306N104 66,123 5,902 9.80 6 0.00 0.0202
2023-01-27 2022-12-31 13F M K S INSTRUMENTS COM 55306N104 60,221 18,753 45.22 5 -99.85 0.0193
2022-11-14 2022-09-30 13F M K S INSTRUMENTS COM 55306N104 41,468 -25,287 -37.88 3,427 -49.98 0.0145
2022-08-12 2022-06-30 13F M K S INSTRUMENTS COM 55306N104 66,755 8,585 14.76 6,851 -21.48 0.0301
2022-05-12 2022-03-31 13F M K S INSTRUMENTS COM 55306N104 58,170 729 1.27 8,725 -12.79 0.0333
2022-02-08 2021-12-31 13F M K S INSTRUMENTS COM 55306N104 57,441 8,671 17.78 10,005 35.94 0.0382
2021-11-15 2021-09-30 13F M K S INSTRUMENTS COM 55306N104 48,770 -6,093 -11.11 7,360 -24.61 0.0303
2021-08-12 2021-06-30 13F M K S INSTRUMENTS COM 55306N104 54,863 -15,952 -22.53 9,763 -25.64 0.0456
2021-05-05 2021-03-31 13F M K S INSTRUMENTS COM 55306N104 70,815 -3,139 -4.24 13,129 18.00 0.0685
2021-02-12 2020-12-31 13F M K S INSTRUMENTS COM 55306N104 73,954 8,909 13.70 11,126 56.59 0.0641
2020-11-12 2020-09-30 13F M K S INSTRUMENTS COM 55306N104 65,045 1,808 2.86 7,105 -0.78 0.0447
2020-08-11 2020-06-30 13F M K S INSTRUMENTS COM 55306N104 63,237 -3,299 -4.96 7,161 32.15 0.0475
2020-04-27 2020-03-31 13F M K S INSTRUMENTS COM 55306N104 66,536 66,536 5,419 0.0442
2018-11-13 2018-09-30 13F MKS INSTRUMENT COM 55306N104 0 -12,022 -100.00 0 -100.00
2018-08-14 2018-06-30 13F/A-1 MKS INSTRUMENT COM 55306N104 12,022 -16,242 -57.47 1,151 -64.79 0.0110
2018-08-14 2018-06-30 13F MKS INSTRUMENT COM 55306N104 12,022 1,151
2018-05-10 2018-03-31 13F M K S INSTRUMENTS COM 55306N104 28,264 10,846 62.27 3,269 98.60 0.0323
2018-02-14 2017-12-31 13F M K S INSTRUMENTS COM 55306N104 17,418 -21,410 -55.14 1,646 -55.10 0.0168
2017-11-14 2017-09-30 13F MKS INSTRUMENT COM 55306N104 38,828 38,828 3,666 0.0387
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.