L3VLUP
ProSign in

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
31 Mar 2026
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 8 May 2026
Managers listing it
28
at least, of 95 tracked, among listed positions
Comparable managers
91
filed both Q4 2025 and Q1 2026; 12 listed it in both
Shares listed
8,500,097
combined, among listed positions
Reported value
$1.4bn
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: 13 buyers (opened or added shares) and 19 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was +196,426.

Managers listing MKTX in Q1 2026

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q4 2025, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

28 of 28 holders

ActionFiling
AQR Capital Management LLC2,683,745$443m0.20%Added+125,64815 May 2026 (the filing on sec.gov)
Fidelity (FMR LLC)1,519,421$251munder 0.1%Trimmed-485,20415 May 2026 (the filing on sec.gov)
Millennium Management LLC1,087,188$179m0.07%Added+785,52315 May 2026 (the filing on sec.gov)
Neuberger Berman Group LLC966,029$159m0.12%Added+416,39027 Oct 2026 (the filing on sec.gov)
Two Sigma Investments LP524,024$86m0.07%Trimmed-9,50315 May 2026 (the filing on sec.gov)
Walleye Capital LLC332,723$55m0.23%Added+164,03513 May 2026 (the filing on sec.gov)
Arrowstreet Capital LP295,470$49munder 0.1%Added+6,72814 May 2026 (the filing on sec.gov)
Point72 Asset Management LP252,825$42m0.05%Newnew15 May 2026 (the filing on sec.gov)
Janus Henderson Group Ltd168,797$28munder 0.1%Added+35018 May 2026 (the filing on sec.gov)
Renaissance Technologies LLC167,100$28munder 0.1%Trimmed-8,90014 May 2026 (the filing on sec.gov)
Invesco Ltd118,332$20munder 0.1%Added+3,71312 May 2026 (the filing on sec.gov)
Citadel Advisors LLC82,159$14munder 0.1%Trimmed-543,04915 May 2026 (the filing on sec.gov)
AllianceBernstein LP41,259$7.5munder 0.1%Added+20,71015 May 2026 (the filing on sec.gov)
Holocene Advisors LP43,799$7.2munder 0.1%Trimmed-171,05615 May 2026 (the filing on sec.gov)
Schonfeld Strategic Advisors LLC42,596$7.0munder 0.1%Trimmed-57,63915 May 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc36,920$6.1munder 0.1%Added+2,94515 May 2026 (the filing on sec.gov)
Baillie Gifford & Co29,032$4.8munder 0.1%Trimmed-10,0838 May 2026 (the filing on sec.gov)
ExodusPoint Capital Management LP23,975$4.0munder 0.1%Newnew14 May 2026 (the filing on sec.gov)
Winton Group Ltd18,018$3.0m0.10%Trimmed-18,34612 May 2026 (the filing on sec.gov)
Squarepoint Ops LLC15,858$2.6munder 0.1%Trimmed-55,80015 May 2026 (the filing on sec.gov)
Man Group PLC13,738$2.3munder 0.1%Trimmed-15,63515 May 2026 (the filing on sec.gov)
Jane Street Group LLC12,740$2.1munder 0.1%Added+34812 May 2026 (the filing on sec.gov)
Quantbot Technologies LP6,940$1.1munder 0.1%Added+1,27913 May 2026 (the filing on sec.gov)
Bridgewater Associates LP5,608$925kunder 0.1%Trimmed-7,65315 May 2026 (the filing on sec.gov)
PDT Partners LLC4,280$706kunder 0.1%Held015 May 2026 (the filing on sec.gov)
Page 1 of 2

Largest increases and reductions, by shares

Q4 2025 to Q1 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 (2)

Exited (6)

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 →