Marketaxess Holdings
MKTX · NASDAQ
Who owns MKTX
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 58.8% of MKTX’s shares.
- BlackRock Institutional Trust Company, N.A.10.6%
- PRIMECAP Management Company9.9%
- North Reef Capital Management LP9.6%
- Vanguard Portfolio Management, LLC5.9%
- Next 6 largest institutions22.9%
- All other shareholders41.2%
| Holder | Shares | % of shares |
|---|---|---|
| BlackRock Institutional Trust Company, N.A. | 3.76M | 10.59% |
| PRIMECAP Management Company | 3.50M | 9.86% |
| North Reef Capital Management LP | 3.40M | 9.55% |
| Vanguard Portfolio Management, LLC | 2.10M | 5.91% |
| AQR Capital Management, LLC | 1.99M | 5.59% |
| Vanguard Capital Management, LLC | 1.55M | 4.35% |
| State Street Investment Management (US) | 1.28M | 3.61% |
| Neuberger Berman, LLC | 1.23M | 3.46% |
| Fidelity Management & Research Company LLC | 1.09M | 3.07% |
| Burgundy Asset Management Ltd. | 1.01M | 2.84% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| iShares Core S&P Small-Cap ETF | 2.13M | 5.98% |
| Vanguard Capital Opportunity Fund | 1.83M | 5.16% |
| Vanguard Total Stock Market Index Fund | 1.08M | 3.03% |
| PRIMECAP Odyssey Aggressive Growth Fund | 937.72K | 2.64% |
| Vanguard Small-Cap Index Fund | 776.00K | 2.18% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders sold $1.09M (7 trades) of MKTX on the open market, with no buys.
| Insider | Type | Shares | Value |
|---|---|---|---|
| Pintoff Scott | Sale | 100 | $16.46K |
| Pintoff Scott | Sale | 100 | $16.33K |
| Cruger William Frank Jr. | Sale | 6.16K | $1.01M |
| Portney Emily Hope | Gift | 2.08K | — |
| Portney Emily Hope | Gift | 2.08K | — |
| Pintoff Scott | Sale | 100 | $16.26K |
| Chwick Jane | Gift | 606 | — |
| Pintoff Scott | Sale | 100 | $11.51K |
| HERNANDEZ CARLOS MAURICIO | Gift | 10.71K | — |
| HERNANDEZ CARLOS MAURICIO | Gift | 10.71K | — |
Congressional trades
Disclosed by members of Congress over the last 12 months
| Member | Type | Amount | Traded |
|---|---|---|---|
| Josh GottheimerHouse | Sale | $1K–$15K | Apr 9, 2026 |
Short interest
Settled Sep 30, 2026
- Shares short
- 3.21M
- Days to cover
- 3.39
- % of shares outstanding
- 9.02%
- Average daily volume
- 946.35K
- Change since last report
- +36.6%
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