Comparable stake leader
BlackRock, Inc.
SEC ownership of MKS INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001049502.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
01 Jun 2026
- Public ticker
- MKSI on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
01 Jun 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001049502
- Issuer location
- Andover, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of MKS INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
01 Jun 2026
13F
13D/G
3/4/5
Lead comparable stake: 8.8%
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 8.8%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
8.8%
Invesco Ltd.
6.5%
VICTORY CAPITAL MANAGEMENT INC
5.6%
VANGUARD PORTFOLIO MANAGEMENT LLC
5.5%
VANGUARD CAPITAL MANAGEMENT LLC
5.2%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
Company
|
8.8%
from 13D/G
|
$1,526,335,861
6,641,730 shares
|
— | 31 Mar 2026 |
| Invesco Ltd. |
13F
13D/G
Company
|
6.5%
from 13D/G
|
$855,228,394
3,721,459 shares
|
— | 31 Mar 2026 |
| VICTORY CAPITAL MANAGEMENT INC |
13D/G
13F
Company
|
5.6%
|
$381,446,885
3,787,201 shares
|
$0 | 30 Jun 2025 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
5.5%
|
$850,311,248
3,700,062 shares
|
$0 | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5.2%
|
$810,961,801
3,528,836 shares
|
$0 | 31 Mar 2026 |
| Capital International Investors |
13F
13D/G
Company
|
4.7%
from 13D/G
|
$452,443,034
1,968,770 shares
|
— | 31 Mar 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13D/G
13F
T. Rowe Price Associates, Inc. · Company
|
4.1%
|
$505,335,328
2,753,871 shares
|
-$252,359,660 | 31 Dec 2025 |
| FMR LLC |
13D/G
13F
Company
|
3.3%
|
$613,012,951
2,243,989 shares
|
$0 | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$41,433,732.
Buys
$0
Insiders: 0
Sells
$41,433,732
Insiders: 13
Net
-$41,433,732
Shares: -150,687
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 150,687
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 67,379 | $0 | $21,797,759 | -$21,797,759 |
| 3-6 | 0 | 72,602 | $0 | $18,333,555 | -$18,333,555 |
| 6-9 | 0 | 1,311 | $0 | $182,886 | -$182,886 |
| 9-12 | 0 | 9,395 | $0 | $1,119,532 | -$1,119,532 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 22 reporting-owner rows connected to MKS INC. Open a relationship link for the CIK-to-CIK filing trail.
Rows
22
Largest Forms 3/4/5 holder
Carlyle Group Inc.
Net 12M change
-$41,433,733
Latest report
12 Jun 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Carlyle Group Inc. | 10%+ Owner | $713,103,113 | Mixed | 08 May 2023 | ||
| Carlyle Partners VI Cayman Holdings, L.P. | 10%+ Owner | $713,103,113 | Mixed | 08 May 2023 | ||
| John Tseng-Chung Lee | President & CEO, Director | $55,072,515 | -$10,858,042 | -16% | Mixed | 22 May 2026 |
| Kathleen Flaherty Burke | EVP, GC & Secretary | $17,660,232 | -$2,456,817 | -12% | Mixed | 11 May 2026 |
| Geoffrey Wild | Director | $11,838,269 | Mixed | 17 Aug 2022 | ||
| Gerald G. Colella | Director | $8,845,388 | -$11,736,749 | -57% | Mixed | 27 May 2026 |
| James Alan Schreiner | Evp & Coo | $8,148,306 | -$2,804,324 | -26% | Mixed | 12 Jun 2026 |
| Elizabeth Mora | Director | $6,088,605 | -$244,836 | -3.9% | Filing P/S | 01 Jun 2026 |
| Eric Robert Taranto | Evp & Gm, Vsd | $4,987,647 | -$2,278,269 | -31% | Mixed | 11 May 2026 |
| David Philip Henry | EVP, Global Str Mktg & GM, MSD | $4,654,221 | -$4,095,953 | -47% | Mixed | 01 Jun 2026 |
| Raj Batra | Director | $3,729,195 | Median | 11 May 2026 | ||
| Mark Milton Gitin | Evp & Gm, Psd | $3,328,164 | Mixed | 15 Feb 2024 | ||
| Joseph B. Donahue | Director | $3,290,265 | -$688,703 | -17% | Filing P/S | 27 May 2026 |
| Seth H. Bagshaw | EVP, CFO & Treasurer | $3,135,791 | Mixed | 22 Feb 2024 | ||
| Jacqueline F. Moloney | Director | $2,739,576 | -$1,100,979 | -29% | Filing P/S | 14 May 2026 |
| Ramakumar Mayampurath | Evp & Cfo | $2,560,738 | -$2,779,379 | -52% | Mixed | 22 May 2026 |
| Peter Cannone III | Director | $2,364,712 | -$732,165 | -24% | Filing P/S | 18 May 2026 |
| Renee Martel Donlan | Evp, Gc & Cco | $2,176,693 | Median | 01 Jun 2026 | ||
| John Edward Williams | Evp & Gm, Psd | $1,614,519 | -$523,744 | -24% | Mixed | 17 Apr 2026 |
| Michelle M. Warner | Director | $1,443,294 | Mixed | 07 May 2024 |
Recent insider transactions for MKS INC
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| James Alan Schreiner | MKSI | Common Stock | Sale | -15.4% | $1,210,370 | $345.82 | -3,500 | 19,201 | 12 Jun 2026 | Direct |
| James Alan Schreiner | MKSI | Common Stock | Sale | -3.33% | $247,905 | $317.42 | -781 | 22,701 | 10 Jun 2026 | Direct |
| Michelle M. McCarthy | MKSI | Common Stock | Sale | -99.9% | $767,270 | $315.23 | -2,434 | 2 | 05 Jun 2026 | Direct |
| David Philip Henry | MKSI | Common Stock | Sale | -36.5% | $1,886,583 | $314.43 | -6,000 | 10,422 | 01 Jun 2026 | Direct |
| Elizabeth Mora | MKSI | Common Stock | Sale | -1.54% | $95,406 | $318.02 | -300 | 19,145 | 01 Jun 2026 | Direct |
| Joseph B. Donahue | MKSI | Common Stock | Sale | -17.3% | $688,703 | $327.95 | -2,100 | 10,033 | 27 May 2026 | Direct |
| Gerald G. Colella | MKSI | Common Stock | Sale | -50% | $6,668,075 | $333.40 | -20,000 | 20,017 | 27 May 2026 | By The Gerald G. Colella 2019 Trust |
| David Philip Henry | MKSI | Common Stock | Sale | -13.3% | $826,250 | $330.50 | -2,500 | 16,341 | 26 May 2026 | Direct |
| Ramakumar Mayampurath | MKSI | Common Stock | Sale | -100% | $2,779,379 | $315.48 | -8,810 | 1 | 22 May 2026 | Direct |
| John Tseng-Chung Lee | MKSI | Common Stock | Sale | -6.46% | $3,154,800 | $315.48 | -10,000 | 144,696 | 22 May 2026 | Direct |
| Peter Cannone III | MKSI | Common Stock | Sale | -14.8% | $409,590 | $303.40 | -1,350 | 7,794 | 18 May 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -10.2% | $312,197 | $312.20 | -1,000 | 8,775 | 14 May 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -12.5% | $446,586 | $318.99 | -1,400 | 9,775 | 13 May 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -18.4% | $911,328 | $319.93 | -2,849 | 12,596 | 11 May 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Award | 7.52% | 782 | 11,175 | 11 May 2026 | Direct | ||
| Wissam G. Jabre | MKSI | Common Stock | Award | 17.4% | 782 | 5,270 | 11 May 2026 | Direct | ||
| Elizabeth Mora | MKSI | Common Stock | Award | 4.19% | 782 | 19,445 | 11 May 2026 | Direct | ||
| Kathleen Flaherty Burke | MKSI | Common Stock | Sale | -8.1% | $1,393,317 | $319.94 | -4,355 | 49,439 | 11 May 2026 | Direct |
| Joseph B. Donahue | MKSI | Common Stock | Award | 6.89% | 782 | 12,133 | 11 May 2026 | Direct | ||
| Peter Cannone III | MKSI | Common Stock | Award | 9.35% | 782 | 9,144 | 11 May 2026 | Direct | ||
| Raj Batra | MKSI | Common Stock | Award | 5.06% | 782 | 16,227 | 11 May 2026 | Direct | ||
| Gerald G. Colella | MKSI | Common Stock | Award | 9.52% | 782 | 8,999 | 11 May 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Tax liability | -15.4% | -826 | 4,555 | 17 Apr 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Options Exercise | 47.8% | 1,741 | 5,381 | 17 Apr 2026 | Direct | ||
| John Edward Williams | MKSI | Restricted Stock Unit | Options Exercise | -20.4% | -1,741 | 6,812 | 17 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Common Stock | Tax liability | -36.1% | -1,375 | 2,436 | 15 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Common Stock | Options Exercise | 3,811 | 3,811 | 15 Apr 2026 | Direct | |||
| Michelle M. McCarthy | MKSI | Restricted Stock Unit | Options Exercise | -34% | -3,811 | 7,388 | 15 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Restricted Stock Unit | Award | 17.6% | 1,673 | 11,199 | 15 Apr 2026 | Direct | ||
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -3.17% | $72,705 | $213.77 | -340 | 10,393 | 12 Mar 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -22.8% | $1,007,318 | $220.52 | -4,568 | 15,445 | 06 Mar 2026 | Direct |
| Elizabeth Mora | MKSI | Common Stock | Sale | -1.58% | $71,832 | $239.44 | -300 | 18,663 | 02 Mar 2026 | Direct |
| James Alan Schreiner | MKSI | Common Stock | Sale | -14.9% | $1,045,500 | $255.00 | -4,100 | 23,402 | 24 Feb 2026 | Direct |
| Gerald G. Colella | MKSI | Common Stock | Sale | -20% | $2,539,675 | $253.97 | -10,000 | 40,017 | 24 Feb 2026 | By The Gerald G. Colella 2019 Trust |
| Gerald G. Colella | MKSI | Common Stock | Sale | -16.7% | $2,528,999 | $252.90 | -10,000 | 50,017 | 20 Feb 2026 | By The Gerald G. Colella 2019 Trust |
| Peter Cannone III | MKSI | Common Stock | Sale | -13% | $322,574 | $258.06 | -1,250 | 8,362 | 20 Feb 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -6.77% | $359,623 | $247.55 | -1,453 | 20,013 | 20 Feb 2026 | Direct |
| David Philip Henry | MKSI | Common Stock | Sale | -9.6% | $523,120 | $261.56 | -2,000 | 18,841 | 20 Feb 2026 | Direct |
| Michelle M. McCarthy | MKSI | Common Stock | Sale | -100% | $366,503 | $250.00 | -1,466 | 0 | 20 Feb 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -7.17% | $205,219 | $247.55 | -829 | 10,733 | 20 Feb 2026 | Direct |
| John Edward Williams | MKSI | Common Stock | Sale | -35.9% | $523,744 | $256.41 | -2,043 | 3,640 | 20 Feb 2026 | Direct |
| Kathleen Flaherty Burke | MKSI | Common Stock | Sale | -7.33% | $1,063,500 | $250.00 | -4,254 | 53,794 | 20 Feb 2026 | Direct |
| John Tseng-Chung Lee | MKSI | Common Stock | Sale | -16.2% | $7,703,242 | $256.77 | -30,000 | 154,696 | 20 Feb 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Tax liability | -11.2% | -2,712 | 21,465 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Common Stock | Options Exercise | 36.6% | 6,473 | 24,177 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Restricted Stock Unit | Options Exercise | -44.6% | -6,473 | 8,029 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Restricted Stock Unit | Award | 13.8% | 1,759 | 14,502 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Common Stock | Tax liability | -16.4% | -4,097 | 20,841 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Common Stock | Options Exercise | 59.3% | 9,282 | 24,939 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Restricted Stock Unit | Options Exercise | -43.4% | -9,282 | 12,093 | 17 Feb 2026 | Direct |
* marks a reported price that did not pass the local price check.