MARKETAXESS HOLDINGS INC (MKTX) Institutional Shareholders
MARKETAXESS HOLDINGS INC (MKTX) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended March 31, 2026. The institutional investors covered on this page collectively reported approximately $5.90B in MKTX holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of MKTX tracked by InsiderSet, reporting ownership valued at approximately $672.32M in its March 31, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $661.40M, representing an estimated loss of -1.62% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 58% of the total disclosed MKTX value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Primecap Management Co/Ca/, Aqr Capital Management Llc, and several other long-term asset managers with concentrated positions in MARKETAXESS HOLDINGS INC (MKTX).
This page ranks the largest institutional MKTX shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
415
Total Reported Value
$5.90B
Largest Holder
Blackrock, Inc.
Largest Position
$672.32M
Insider Transactions (90d)
15
Latest Filing Quarter
Q2 2026
New Institutional Positions
44
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.01% | 4,075,154 | $672,318,906 | $661,397,494 | -$10,921,412 | -1.62% | |
| Primecap Management Co/Ca/ | 0.43% | 3,347,125 | $552,208,683 | $543,238,388 | -$8,970,296 | -1.62% | |
| Aqr Capital Management Llc | 0.20% | 2,683,745 | $442,764,395 | $435,571,814 | -$7,192,581 | -1.62% | |
| Vanguard Portfolio Management Llc | 0.02% | 2,163,671 | $356,962,442 | $351,163,803 | -$5,798,639 | -1.62% | |
| North Reef Capital Management Lp | 10.65% | 1,875,000 | $309,337,500 | $304,312,500 | -$5,025,000 | -1.62% | |
| Vanguard Capital Management Llc | 0.01% | 1,609,259 | $265,495,550 | $261,182,736 | -$4,312,814 | -1.62% | |
| Fmr Llc | 0.01% | 1,519,421 | $250,674,082 | $246,602,028 | -$4,072,054 | -1.62% | |
| State Street Corp | 0.01% | 1,280,857 | $211,315,788 | $207,883,091 | -$3,432,697 | -1.62% | |
| Millennium Management Llc | 0.13% | 1,087,188 | $179,364,276 | $176,450,612 | -$2,913,664 | -1.62% | |
| Bank Of Montreal | 0.07% | 1,020,559 | $168,371,804 | $165,636,726 | -$2,735,078 | -1.62% | |
| Neuberger Berman Group Llc | 0.12% | 966,029 | $159,375,424 | $156,786,507 | -$2,588,917 | -1.62% | |
| Geode Capital Management, Llc | 0.01% | 862,987 | $142,403,175 | $140,062,790 | -$2,340,385 | -1.64% | |
| Guardcap Asset Management Ltd | 6.09% | 643,370 | $106,351,076 | $104,418,951 | -$1,932,125 | -1.82% | |
| Dimensional Fund Advisors Lp | 0.02% | 581,484 | $95,932,833 | $94,374,853 | -$1,557,980 | -1.62% | |
| Two Sigma Investments, Lp | 0.07% | 524,024 | $86,453,480 | $85,049,095 | -$1,404,385 | -1.62% | |
| Goldman Sachs Group Inc | 0.01% | 509,043 | $83,981,929 | $82,617,679 | -$1,364,250 | -1.62% | |
| Morgan Stanley | 0.00% | 490,537 | $80,929,006 | $79,614,155 | -$1,314,851 | -1.62% | |
| Findlay Park Partners Llp | 1.11% | 480,600 | $79,289,388 | $78,001,380 | -$1,288,008 | -1.62% | |
| Charles Schwab Investment Management Inc | 0.01% | 338,507 | $55,846,885 | $54,939,686 | -$907,199 | -1.62% | |
| Walleye Capital Llc | 0.34% | 332,723 | $54,892,641 | $54,000,943 | -$891,698 | -1.62% | |
| Bnp Paribas Financial Markets | 0.03% | 319,302 | $52,678,444 | $51,822,715 | -$855,729 | -1.62% | |
| Arrowstreet Capital, Limited Partnership | 0.03% | 295,470 | $48,746,641 | $47,954,781 | -$791,860 | -1.62% | |
| Rdst Capital Llc | 4.69% | 295,267 | $48,713,150 | $47,921,834 | -$791,316 | -1.62% | |
| Bank Of New York Mellon Corp | 0.01% | 289,940 | $47,834,350 | $47,057,262 | -$777,088 | -1.62% | |
| Ubs Group Ag | 0.01% | 272,238 | $44,913,826 | $44,184,227 | -$729,599 | -1.62% | |
| Bank Of America Corp | 0.00% | 263,858 | $43,531,294 | $42,824,153 | -$707,141 | -1.62% | |
| Amundi | 0.01% | 258,708 | $42,681,646 | $41,988,308 | -$693,338 | -1.62% | |
| Point72 Asset Management, L.P. | 0.07% | 252,825 | $41,711,069 | $41,033,498 | -$677,572 | -1.62% | |
| Driehaus Capital Management Llc | 0.29% | 239,256 | $39,472,455 | $38,831,249 | -$641,206 | -1.62% | |
| Northern Trust Corp | 0.01% | 236,350 | $38,993,024 | $38,359,605 | -$633,419 | -1.62% | |
| Vanguard Fiduciary Trust Co | 0.01% | 229,427 | $37,850,866 | $37,236,002 | -$614,864 | -1.62% | |
| Storebrand Asset Management As | 0.01% | 92,198 | $37,348,124 | $14,963,735 | -$22,384,389 | -59.93% | |
| Champlain Investment Partners, Llc | 0.44% | 210,076 | $34,658,338 | $34,095,335 | -$563,003 | -1.62% | |
| Victory Capital Management Inc | 0.02% | 204,932 | $33,809,681 | $33,260,464 | -$549,217 | -1.62% | |
| Bnp Paribas Asset Management Holding S.A. | 0.04% | 203,425 | $33,561,057 | $33,015,878 | -$545,179 | -1.62% | |
| Public Sector Pension Investment Board | 0.10% | 192,230 | $31,714,105 | $31,198,929 | -$515,176 | -1.62% | |
| Principal Financial Group Inc | 0.02% | 181,798 | $29,993,034 | $29,505,815 | -$487,219 | -1.62% | |
| Connor, Clark & Lunn Investment Management Ltd. | 0.07% | 174,059 | $28,716,254 | $28,249,776 | -$466,478 | -1.62% | |
| Ieq Capital, Llc | 0.13% | 173,891 | $28,688,549 | $28,222,509 | -$466,040 | -1.62% | |
| Janus Henderson Group Plc | 0.01% | 168,797 | $27,849,291 | $27,395,753 | -$453,538 | -1.63% | |
| Renaissance Technologies LLC | Jim Simons | 0.04% | 167,100 | $27,568,158 | $27,120,330 | -$447,828 | -1.62% |
| Cooke & Bieler Lp | 0.31% | 238,755 | $27,096,305 | $38,749,937 | +$11,653,632 | +43.01% | |
| Sone Capital Management, Llc | 2.22% | 159,966 | $26,391,191 | $25,962,482 | -$428,709 | -1.62% | |
| Nuveen, Llc | 0.01% | 148,081 | $24,430,403 | $24,033,546 | -$396,857 | -1.62% | |
| Healthcare Of Ontario Pension Plan Trust Fund | 0.04% | 145,628 | $24,025,707 | $23,635,424 | -$390,283 | -1.62% | |
| Raymond James Financial Inc | 0.01% | 121,635 | $20,067,298 | $19,741,361 | -$325,938 | -1.62% | |
| Invesco Ltd. | 0.00% | 118,332 | $19,522,413 | $19,205,284 | -$317,129 | -1.62% | |
| Davis Asset Management, L.P. | 0.52% | 108,846 | $17,957,413 | $17,665,706 | -$291,707 | -1.62% | |
| Flossbach Von Storch Se | 0.08% | 108,100 | $17,834,338 | $17,544,630 | -$289,708 | -1.62% | |
| Ubs Am, A Distinct Business Unit Of Ubs Asset Management Americas Llc | 0.00% | 107,110 | $17,671,009 | $17,383,953 | -$287,056 | -1.62% |
Frequently asked questions about MKTX
Who owns the most MKTX stock?
The largest holders of MKTX are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for MARKETAXESS HOLDINGS INC (MKTX).
Is MKTX widely held by superinvestors?
Many widely followed stocks like MKTX appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly MKTX is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.