Security key
57060D108
MARKETAXESS HOLDINGS INC - Common Stock, $0.003 par value (MKTX)
CUSIP: 57060D108
Q1 2026 13F Holders as of 31 Mar 2026
- Security type / class
- Equity / Common Stock, $0.003 par value
- Total 13F shares
- 38,240,635
- Total 13F value
- $6,309,513,139
- Share change
- +1,575,587
- Put/Call ratio
- 31%
- SEC-reported price per share
- $164.98
- Number of holders
- 451
- Value change
- +$239,098,177
- Number of buys
- 237
- Number of sells
- 240
- Shares outstanding
- 35,549,738
Holder snapshot
7 signals
Open additional details 1 more signal available
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q1 2026
Institutions
451
Top holders
10
MKTX full security history
Ownership snapshot
Full 13F holder table
MARKETAXESS HOLDINGS INC SEC filings
MARKETAXESS HOLDINGS INC company facts
Broader feeds
Ownership snapshot
Top reported holders of MKTX - MARKETAXESS HOLDINGS INC - Common Stock, $0.003 par value (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
15/15
Latest evidence
31 Mar 2026
13D/G
13F
3/4/5
Lead comparable stake: 11%
13D/G row: BlackRock, Inc.
Showing 1-6 of 15 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 11%.
15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
11%
VANGUARD PORTFOLIO MANAGEMENT LLC
6.1%
VANGUARD CAPITAL MANAGEMENT LLC
5.3%
GUARDIAN CAPITAL LP
4.8%
FMR LLC
4.2%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13D/G
13F
Company
|
11%
|
$731,260,235
4,034,537 shares
|
+$64,142,960 | 31 Jan 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
Vanguard Portfolio Management
|
6.1%
|
$357,691,531
2,168,085 shares
|
$0 | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
Vanguard Capital Management
|
5.3%
|
$312,158,376
1,892,096 shares
|
$0 | 31 Mar 2026 |
| GUARDIAN CAPITAL LP |
13D/G
|
4.8%
|
$391,918,458
1,789,582 shares
|
$0 | 31 Dec 2024 |
| FMR LLC |
13F
13D/G
Company
|
4.2%
from 13D/G
|
$363,338,135
2,004,625 shares
|
— | 31 Dec 2025 |
| T. Rowe Price Investment Management, Inc. |
13D/G
13F
Company
|
3.7%
|
$238,843,567
1,370,694 shares
|
$0 | 30 Sep 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q1 2026
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
451
Shares
38,240,635
Rows available
451
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q1 2026 vs Q1 2026 Across Filers
Q1 2026 holders
451
Q1 2026 holders
451
Holder diff
0
| Investor | Q1 2026 Shares | Q1 2026 Shares | Share Diff | Share Chg % | Q1 2026 value | Q1 2026 value | Value change | Value Chg % |
|---|