Marketaxess Holdings Inc (MKTX) — 13F Filings Explorer (Q2 2026)

MKTX ranks #1554 out of 37501 tracked stocks by institutional interest — one of the most closely watched names in our coverage.

MKTX is a disclosed holding of Cliff Asness (AQR Capital Management), one of the tracked superinvestors on AlphaSMO — it makes up 0.1% of that fund's own 13F portfolio.

MKTX is a top-conviction position for North Reef Capital Management LP — at 14.8% of their entire disclosed 13F portfolio, it's one of their largest single bets, not just a passing allocation.

The largest dollar stake in MKTX belongs to BlackRock, Inc., but the position matters far more to North Reef Capital Management LP, who has 14.8% of their own portfolio riding on it — a reminder that the biggest holder by size and the holder with the biggest bet aren't always the same fund.

North Reef Capital Management LP has added to its MKTX position for two straight quarters, increasing it by $93.6M to reach $385.3M today.

Cliff Asness has trimmed its MKTX position for two straight quarters, cutting it by $240.9M while still holding $222.8M.

MKTX is up 0.2% today, and institutions have been net buyers of $967.9M this quarter — today's price move and the underlying institutional flow are pointing the same direction.

MKTX posted net income of $306.4M over the trailing twelve months, and currently trades at a P/E of 19.7.

• Profitable — net income of $306.4M over the trailing twelve months
• Revenue grew 3.9% year over year
• Net income improved year over year, from $222.8M to $306.4M
• Generated $382.1M in positive operating cash flow
• Liabilities run 0.68x equity — within a conventional range