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MKTX in the 13F filings

Marketaxess Holdings Inc · CUSIP 57060D108

Sector · Other financial servicesTheme · Financial services· L3VLUP-defined
Quarter
Q2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024Q2 2024Q1 2024Q4 2023Q3 2023
Quarter end
30 Jun 2026
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 3 Aug 2026
Managers listing it
31
at least, of 95 tracked, among listed positions
Comparable managers
91
filed both Q1 2026 and Q2 2026; 11 listed it in both
Shares listed
7,149,481
combined, among listed positions
Reported value
$809m
combined, at the quarter end

AllianceBernstein LP. Values in this filing are at the previous quarter end's prices; its share count is the quarter end's.

Among the 91 comparable managers: 19 buyers (opened or added shares) and 15 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was -1,350,616.

Managers listing MKTX in Q2 2026

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q1 2026, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

31 of 31 holders

ActionFiling
AQR Capital Management LLC1,987,288$223m0.08%Trimmed-696,45714 Aug 2026 (the filing on sec.gov)
Fidelity (FMR LLC)1,404,998$159munder 0.1%Trimmed-114,42313 Aug 2026 (the filing on sec.gov)
Neuberger Berman Group LLC1,229,929$140m0.09%Added+263,90027 Oct 2026 (the filing on sec.gov)
Two Sigma Investments LP543,890$62munder 0.1%Added+19,86614 Aug 2026 (the filing on sec.gov)
Citadel Advisors LLC481,689$55munder 0.1%Added+399,5302 Sep 2026 (the filing on sec.gov)
Renaissance Technologies LLC200,000$23munder 0.1%Added+32,90013 Aug 2026 (the filing on sec.gov)
Freestone Grove Partners LP172,799$20m0.13%Newnew14 Aug 2026 (the filing on sec.gov)
Invesco Ltd140,817$16munder 0.1%Added+22,48514 Aug 2026 (the filing on sec.gov)
Tudor Investment Corp137,847$16munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
Arrowstreet Capital LP122,005$14munder 0.1%Trimmed-173,46513 Aug 2026 (the filing on sec.gov)
Millennium Management LLC109,590$12munder 0.1%Trimmed-977,59814 Aug 2026 (the filing on sec.gov)
Walleye Capital LLC94,002$11munder 0.1%Trimmed-238,7213 Aug 2026 (the filing on sec.gov)
Jane Street Group LLC77,353$8.8munder 0.1%Added+64,61314 Aug 2026 (the filing on sec.gov)
Brevan Howard Capital Management LP51,050$5.8munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
First Eagle Investment Management LLC49,577$5.6munder 0.1%Added+49,5555 Aug 2026 (the filing on sec.gov)
D. E. Shaw & Co.47,977$5.4munder 0.1%Added+44,66314 Aug 2026 (the filing on sec.gov)
Marshall Wace LLP39,090$4.4munder 0.1%Newnew13 Aug 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc38,521$4.4munder 0.1%Added+1,60114 Aug 2026 (the filing on sec.gov)
Holocene Advisors LP38,269$4.3munder 0.1%Trimmed-5,53014 Aug 2026 (the filing on sec.gov)
Susquehanna International Group LLP32,579$3.7munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
Squarepoint Ops LLC32,462$3.7munder 0.1%Added+16,60414 Aug 2026 (the filing on sec.gov)
PDT Partners LLC28,171$3.2m0.17%Added+23,89114 Aug 2026 (the filing on sec.gov)
AllianceBernstein LP12,715$2.1munder 0.1%Trimmed-28,54414 Aug 2026 (the filing on sec.gov)
Janus Henderson Group Ltd16,600$1.9munder 0.1%Trimmed-152,19714 Aug 2026 (the filing on sec.gov)
Man Group PLC14,008$1.6munder 0.1%Added+27014 Aug 2026 (the filing on sec.gov)
Page 1 of 2

Largest increases and reductions, by shares

Q1 2026 to Q2 2026, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (6)

Exited (3)

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
14 in Q3 2024 to 10 in Q2 2026

Tracked managers listing it, at least.

051015202014201620182020202220242026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
MKTX by quarter
QuarterHoldersReported valueBuyersSellers
Q2 20132$24mn.a.n.a.
Q3 20133$53mn.a.n.a.
Q4 20133$65mn.a.n.a.
Q1 20143$75mn.a.n.a.
Q2 20142$104mn.a.n.a.
Q3 20144$158mn.a.n.a.
Q4 20143$170mn.a.n.a.
Q1 20153$215mn.a.n.a.
Q2 20154$381mn.a.n.a.
Q3 20154$426mn.a.n.a.
Q4 20155$566mn.a.n.a.
Q1 20165$717mn.a.n.a.
Q2 20168$1.1bnn.a.n.a.
Q3 20168$1.1bnn.a.n.a.
Q4 20169$785mn.a.n.a.
Q1 201711$1.3bnn.a.n.a.
Q2 201711$1.6bnn.a.n.a.
Q3 20179$1.5bnn.a.n.a.
Q4 201713$2.4bnn.a.n.a.
Q1 201813$2.7bnn.a.n.a.
Q2 201812$2.4bnn.a.n.a.
Q3 201811$2.1bnn.a.n.a.
Q4 201812$2.5bnn.a.n.a.
Q1 201911$2.7bnn.a.n.a.
Q2 201912$3.4bnn.a.n.a.
Q3 201910$3.2bnn.a.n.a.
Q4 201912$3.3bnn.a.n.a.
Q1 202018$2.5bnn.a.n.a.
Q2 202016$3.2bnn.a.n.a.
Q3 202015$2.7bnn.a.n.a.
Q4 202016$3.4bnn.a.n.a.
Q1 202117$3.4bnn.a.n.a.
Q2 202113$3.6bnn.a.n.a.
Q3 202112$3.1bnn.a.n.a.
Q4 202114$3.2bnn.a.n.a.
Q1 202214$2.3bnn.a.n.a.
Q2 202218$1.6bnn.a.n.a.
Q3 202216$672mn.a.n.a.
Q4 20229$671mn.a.n.a.
Q1 20237$1.1bnn.a.n.a.
Q2 20239$756mn.a.n.a.
Q3 202314$595mn.a.n.a.
Q4 202313$898m85
Q1 20249$353m55
Q2 202414$562m114
Q3 202414$1.0bn95
Q4 202415$1.0bn96
Q1 202513$1.0bn95
Q2 202519$1.2bn139
Q3 202516$670m133
Q4 202514$892m1620
Q1 202613$1.0bn1319
Q2 202610$475m1915

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

MKTX and V →MKTX and AXP →MKTX and BAC →Choose a stock to compare with MKTX →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own MKTX, latest filings →Back to the 13F Explorer →