William Blair & Company’s MarketAxess Holdings MKTX Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2025
Q4
Sell
-1,687
Closed -$294K 1917
2025
Q3
$294K Buy
1,687
+400
+31% +$78.2K ﹤0.01% 1311
2025
Q2
$287K Buy
+1,287
New +$283K ﹤0.01% 1285
2024
Q1
Sell
-955
Closed -$280K 1830
2023
Q4
$280K Buy
+955
New +$231K ﹤0.01% 1283
2023
Q3
Sell
-2,062
Closed -$539K 1823
2023
Q2
$539K Sell
2,062
-689
-25% -$206K ﹤0.01% 1030
2023
Q1
$1.08M Buy
2,751
+299
+12% +$106K ﹤0.01% 813
2022
Q4
$684K Buy
2,452
+84
+4% +$21.6K ﹤0.01% 948
2022
Q3
$527K Sell
2,368
-228
-9% -$58.5K ﹤0.01% 1020
2022
Q2
$665K Sell
2,596
-2,587
-50% -$707K ﹤0.01% 975
2022
Q1
$1.76M Sell
5,183
-698
-12% -$253K 0.01% 730
2021
Q4
$2.42M Sell
5,881
-249
-4% -$98.2K 0.01% 676
2021
Q3
$2.58M Sell
6,130
-95
-2% -$43.6K 0.01% 635
2021
Q2
$2.89M Sell
6,225
-230
-4% -$109K 0.01% 597
2021
Q1
$3.21M Sell
6,455
-608
-9% -$324K 0.01% 555
2020
Q4
$4.03M Sell
7,063
-816
-10% -$444K 0.01% 478
2020
Q3
$3.79M Sell
7,879
-866
-10% -$428K 0.02% 453
2020
Q2
$4.38M Sell
8,745
-693
-7% -$323K 0.02% 404
2020
Q1
$3.14M Sell
9,438
-532
-5% -$185K 0.02% 431
2019
Q4
$3.78M Buy
9,970
+8,393
+532% +$3.08M 0.02% 457
2019
Q3
$516K Sell
1,577
-2,864
-64% -$1.03M ﹤0.01% 931
2019
Q2
$1.43M Sell
4,441
-455
-9% -$132K 0.01% 665
2019
Q1
$1.21M Sell
4,896
-445
-8% -$101K 0.01% 685
2018
Q4
$1.13M Sell
5,341
-1,362
-20% -$282K 0.01% 660
2018
Q3
$1.2M Sell
6,703
-67,815
-91% -$13M 0.01% 689
2018
Q2
$14.7M Buy
74,518
+2,549
+4% +$528K 0.1% 192
2018
Q1
$15.6M Sell
71,969
-20,367
-22% -$4.19M 0.11% 180
2017
Q4
$18.6M Buy
92,336
+23,438
+34% +$4.42M 0.13% 173
2017
Q3
$12.7M Sell
68,898
-1,147
-2% -$219K 0.1% 207
2017
Q2
$14.1M Sell
70,045
-10,460
-13% -$2M 0.11% 203
2017
Q1
$15.7M Sell
80,505
-3,053
-4% -$553K 0.13% 178
2016
Q4
$12.3M Buy
83,558
+2,271
+3% +$361K 0.11% 196
2016
Q3
$13.5M Buy
81,287
+65,808
+425% +$10.7M 0.12% 189
2016
Q2
$2.25M Buy
+15,479
New +$2.06M 0.02% 453
2015
Q3
Sell
-4,527
Closed -$419K 1490
2015
Q2
$419K Buy
+4,527
New +$399K ﹤0.01% 1820

Other funds holding MKTX

William Blair & Company's MKTX Position: Q4 2025 in Review

William Blair & Company sold out of MarketAxess Holdings (MKTX) in Q4 2025, closing a stake of 1,687 shares — an estimated $294K sold.

William Blair & Company first reported a position in MKTX in Q2 2015 and held it in 33 quarters. The position peaked at $18.6M in Q4 2017. 486 funds tracked by Wall St. Rank hold MKTX as of Q4 2025.

  • William Blair & Company reported no remaining MarketAxess Holdings position as of Q4 2025 after selling out during the quarter.
  • William Blair & Company sold 1,687 MarketAxess Holdings shares in Q4 2025, an estimated $294K.
  • William Blair & Company first reported a position in MarketAxess Holdings in Q2 2015 and held it in 33 quarters.
  • William Blair & Company's MarketAxess Holdings position peaked at $18.6M in Q4 2017.
  • 486 funds tracked by Wall St. Rank held MarketAxess Holdings as of Q4 2025.

Based on William Blair & Company's 13F filing for Q4 2025, filed 17 Feb 2026.