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 June 30, 2026. The institutional investors covered on this page collectively reported approximately $4.46B 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 $453.94M in its June 30, 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 $653.25M, representing an estimated gain of +43.91% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 55% of the total disclosed MKTX value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Primecap Management Co/Ca/, North Reef Capital Management Lp, 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
382
Total Reported Value
$4.46B
Largest Holder
Blackrock, Inc.
Largest Position
$453.94M
Insider Transactions (90d)
6
Latest Filing Quarter
Q2 2026
New Institutional Positions
36
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% | 3,999,836 | $453,941,390 | $653,253,216 | +$199,311,826 | +43.91% | |
| Primecap Management Co/Ca/ | 0.24% | 3,504,905 | $397,771,671 | $572,421,085 | +$174,649,414 | +43.91% | |
| North Reef Capital Management Lp | 14.77% | 3,395,000 | $385,298,550 | $554,471,400 | +$169,172,850 | +43.91% | |
| Vanguard Portfolio Management Llc | 0.01% | 2,100,273 | $238,359,983 | $343,016,586 | +$104,656,603 | +43.91% | |
| Aqr Capital Management Llc | 0.08% | 1,987,288 | $222,755,056 | $324,563,876 | +$101,808,820 | +45.70% | |
| Vanguard Capital Management Llc | 0.00% | 1,546,670 | $175,531,578 | $252,602,144 | +$77,070,566 | +43.91% | |
| Fmr Llc | 0.01% | 1,404,998 | $159,453,202 | $229,464,273 | +$70,011,071 | +43.91% | |
| State Street Corp | 0.00% | 1,281,769 | $145,433,788 | $209,338,513 | +$63,904,725 | +43.94% | |
| Neuberger Berman Group Llc | 0.09% | 1,229,929 | $139,584,647 | $200,872,004 | +$61,287,357 | +43.91% | |
| Goldman Sachs Group Inc | 0.01% | 1,031,309 | $117,043,220 | $168,433,386 | +$51,390,166 | +43.91% | |
| Bank Of Montreal | 0.04% | 1,017,024 | $115,422,088 | $166,100,360 | +$50,678,272 | +43.91% | |
| Geode Capital Management, Llc | 0.01% | 994,772 | $112,915,474 | $162,466,163 | +$49,550,689 | +43.88% | |
| Van Eck Associates Corp | 0.06% | 924,617 | $104,934,783 | $151,008,448 | +$46,073,665 | +43.91% | |
| Dimensional Fund Advisors Lp | 0.01% | 597,894 | $67,847,626 | $97,648,048 | +$29,800,422 | +43.92% | |
| Norges Bank | 0.01% | 572,422 | $64,964,173 | $93,487,961 | +$28,523,788 | +43.91% | |
| Guardcap Asset Management Ltd | 4.42% | 536,324 | $62,163,314 | $87,592,436 | +$25,429,122 | +40.91% | |
| Two Sigma Investments, Lp | 0.05% | 543,890 | $61,726,076 | $88,828,115 | +$27,102,039 | +43.91% | |
| Azora Capital Lp | 2.45% | 513,081 | $58,229,563 | $83,796,389 | +$25,566,826 | +43.91% | |
| Davis Asset Management, L.P. | 1.44% | 500,000 | $56,745,000 | $81,660,000 | +$24,915,000 | +43.91% | |
| Citadel Advisors Llc | 0.03% | 481,689 | $54,666,885 | $78,669,447 | +$24,002,562 | +43.91% | |
| Jpmorgan Chase & Co | 0.00% | 438,001 | $48,329,209 | $71,534,323 | +$23,205,114 | +48.01% | |
| Morgan Stanley | 0.00% | 422,864 | $47,991,093 | $69,062,148 | +$21,071,055 | +43.91% | |
| Los Angeles Capital Management Llc | 0.16% | 392,065 | $44,495,458 | $64,032,056 | +$19,536,598 | +43.91% | |
| Charles Schwab Investment Management Inc | 0.00% | 330,815 | $37,544,194 | $54,028,706 | +$16,484,512 | +43.91% | |
| Bank Of America Corp | 0.00% | 303,517 | $34,446,181 | $49,570,396 | +$15,124,215 | +43.91% | |
| Ubs Group Ag | 0.01% | 278,745 | $31,634,770 | $45,524,633 | +$13,889,863 | +43.91% | |
| Bank Of New York Mellon Corp | 0.00% | 257,642 | $29,239,844 | $42,078,091 | +$12,838,247 | +43.91% | |
| Rdst Capital Llc | 2.32% | 247,112 | $28,044,741 | $40,358,332 | +$12,313,591 | +43.91% | |
| Northern Trust Corp | 0.00% | 246,521 | $27,977,668 | $40,261,810 | +$12,284,142 | +43.91% | |
| Janus Henderson Group Plc | 0.01% | 168,797 | $27,849,291 | $27,567,926 | -$281,365 | -1.01% | |
| Cooke & Bieler Lp | 0.31% | 238,755 | $27,096,305 | $38,993,467 | +$11,897,162 | +43.91% | |
| Vanguard Fiduciary Trust Co | 0.01% | 223,656 | $25,382,719 | $36,527,498 | +$11,144,779 | +43.91% | |
| Hrt Financial Lp | 0.04% | 205,854 | $23,362,000 | $33,620,075 | +$10,258,075 | +43.91% | |
| Bnp Paribas Asset Management Holding S.A. | 0.02% | 204,309 | $23,187,028 | $33,367,746 | +$10,180,718 | +43.91% | |
| Victory Capital Management Inc | 0.01% | 202,731 | $23,007,941 | $33,110,027 | +$10,102,086 | +43.91% | |
| Renaissance Technologies LLC | Jim Simons | 0.03% | 200,000 | $22,698,000 | $32,664,000 | +$9,966,000 | +43.91% |
| Connor, Clark & Lunn Investment Management Ltd. | 0.04% | 186,658 | $21,183,816 | $30,484,985 | +$9,301,169 | +43.91% | |
| Principal Financial Group Inc | 0.01% | 173,312 | $19,669,179 | $28,305,316 | +$8,636,137 | +43.91% | |
| Freestone Grove Partners Lp | 0.13% | 172,799 | $19,610,959 | $28,221,533 | +$8,610,574 | +43.91% | |
| Public Sector Pension Investment Board | 0.05% | 157,338 | $17,856,290 | $25,696,442 | +$7,840,152 | +43.91% | |
| Ubs Am, A Distinct Business Unit Of Ubs Asset Management Americas Llc | 0.00% | 107,110 | $17,671,009 | $17,493,205 | -$177,804 | -1.01% | |
| Sone Capital Management, Llc | 1.34% | 155,522 | $17,650,192 | $25,399,853 | +$7,749,661 | +43.91% | |
| Nuveen, Llc | 0.00% | 148,468 | $16,849,635 | $24,247,794 | +$7,398,159 | +43.91% | |
| Invesco Ltd. | 0.00% | 140,817 | $15,981,321 | $22,998,232 | +$7,016,911 | +43.91% | |
| Tudor Investment Corp Et Al | 0.06% | 137,847 | $15,644,256 | $22,513,172 | +$6,868,916 | +43.91% | |
| Champlain Investment Partners, Llc | 0.40% | 136,087 | $15,444,514 | $22,225,729 | +$6,781,215 | +43.91% | |
| Arrowstreet Capital, Limited Partnership | 0.01% | 122,005 | $13,846,347 | $19,925,857 | +$6,079,510 | +43.91% | |
| M&G Plc | 0.07% | 121,309 | $13,707,917 | $19,812,186 | +$6,104,269 | +44.53% | |
| Bank Of Nova Scotia | 0.02% | 115,410 | $13,097,881 | $18,848,761 | +$5,750,880 | +43.91% | |
| Cibc Bancorp Usa Inc. | 0.02% | 114,968 | $13,047,706 | $18,776,574 | +$5,728,868 | +43.91% |
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.