MKS Inc.
US ˙ NasdaqGS ˙ US55306N1046

SecurityMKSI / MKS Inc.
InstitutionKBC Group NV
Latest Disclosed Ownership26,137 shares
Latest Disclosed Value $ 6,007
KBC Group NV reports 1,181.85% increase in ownership of MKSI / MKS Inc.

On May 7, 2026 - KBC Group NV filed a 13F-HR form disclosing ownership of 26,137 shares of MKS Inc. (US:MKSI) valued at $6,006,544 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 2,039 shares of MKS Inc.. The current value of the position is $8,759,816 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)
2026-05-07 2026-03-31 13F MKS COM 55306N104 26,137 24,098 1,181.85 6 0.0077
2026-01-26 2025-12-31 13F MKS COM 55306N104 2,039 251 14.04 0 0.0007
2026-01-20 2025-09-30 13F MKS COM 55306N104 1,788 0 0.00 0 0.0005
2025-08-08 2025-06-30 13F MKS COM 55306N104 1,788 -1,294 -41.99 0 0.0005
2025-04-25 2025-03-31 13F MKS INSTRS COM 55306N104 3,082 -27,730 -90.00 0 -100.00 0.0008
2025-01-22 2024-12-31 13F MKS INSTRS COM 55306N104 30,812 29,099 1,698.72 3 0.0089
2024-11-06 2024-09-30 13F MKS INSTRS COM 55306N104 1,713 0 0.00 0 0.0006
2024-07-17 2024-06-30 13F MKS INSTRS COM 55306N104 1,713 323 23.24 0 0.0007
2024-05-08 2024-03-31 13F MKS INSTRS COM 55306N104 1,390 164 13.38 0 0.0006
2024-02-13 2023-12-31 13F MKS INSTRS COM 55306N104 1,226 285 30.29 0 0.0004
2024-02-15 2023-09-30 13F/A-1 MKS INSTRS COM 55306N104 941 941 0 0.0003
2018-11-14 2018-09-30 13F MKS INSTRUMENT COM 55306N104 0 -2,734 -100.00 0 -100.00
2018-08-03 2018-06-30 13F MKS INSTRUMENT COM 55306N104 2,734 0 0.00 262 -17.09 0.0023
2018-08-03 2018-03-31 13F/A-1 MKS INSTRUMENT COM 55306N104 2,734 -13,757 -83.42 316 -79.72 0.0029
2018-05-09 2018-03-31 13F MKS INSTRUMENT COM 55306N104 2,734 -13,757 316
2018-08-03 2017-12-31 13F/A-1 MKS INSTRUMENT COM 55306N104 16,491 0 0.00 1,558 0.00 0.0133
2018-02-07 2017-12-31 13F MKS INSTRUMENT COM 55306N104 16,491 0 1,558
2017-11-13 2017-09-30 13F MKS INSTRUMENT COM 55306N104 16,491 0 0.00 1,558 40.36 0.0141
2017-08-04 2017-06-30 13F MKS INSTRUMENT COM 55306N104 16,491 0 0.00 1,110 -2.12 0.0107
2017-05-10 2017-03-31 13F MKS INSTRUMENT COM 55306N104 16,491 0 0.00 1,134 15.71 0.0102
2017-02-16 2016-12-31 13F MKS INSTRUMENT COM 55306N104 16,491 0 0.00 980 19.51 0.0097
2016-11-03 2016-09-30 13F MKS INSTRUMENT COM 55306N104 16,491 16,491 0.00 820 0.0097
2016-02-11 2015-12-31 13F MKS INSTRUMENT COM 55306N104 0 -10,651 -100.00 0 -100.00
2015-11-12 2015-09-30 13F MKS INSTRUMENT COM 55306N104 10,651 -12,867 -54.71 357 -59.98 0.0072
2015-12-16 2015-06-30 13F/A-1 MKS INSTRUMENT COM 55306N104 23,518 -6,982 -22.89 892 -13.48 0.0115
2015-07-31 2015-06-30 13F MKS INSTRUMENT COM 55306N104 23,518 892
2015-12-16 2015-03-31 13F/A-1 MKS INSTRUMENT COM 55306N104 30,500 0 0.00 1,031 -7.62 0.0131
2015-04-30 2015-03-31 13F MKS INSTRUMENT COM 55306N104 30,500 1,031
2015-12-15 2014-12-31 13F/A-1 MKS INSTRUMENT COM 55306N104 30,500 30,500 108.26 1,116 186.89 0.0133
2015-02-12 2014-12-31 13F MKS INSTRUMENT COM 55306N104 30,500 1,116
2013-11-06 2013-09-30 13F MKS INSTRUMENTS COM 55306N104 0 -14,645 -100.00 0 -100.00
2013-07-29 2013-06-30 13F MKS INSTRUMENTS COM 55306N104 14,645 14,645 389 0.0072
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.