MarketAxess Holdings (NASDAQ:MKTX) shares were in focus Wednesday after the fixed-income platform operator reported surging volume across its specialized trading protocols for December and the fourth quarter of 2025.
The results highlight a successful push into "agentic" and automated trading styles, with portfolio trading ADV hitting a record $1.5 billion, a 41% increase over the previous year.
The company’s growth was most pronounced in the U.S. credit portfolio trading sector, where its estimated market share reached a record 20.6%.
This momentum was fueled by an all-time high in U.S. high-yield portfolio trading market share, which spiked to 27.7% in December.
Additionally, the dealer-initiated channel saw a 32% rise in ADV, bolstered by a massive 185% increase in Mid-X volume, which surpassed $3 billion for the month.
Despite the volume records, the company noted a decline in total credit fees per million (FPM) on both a yearly and quarterly basis.
Management attributed this slide primarily to protocol mix—as higher-volume, lower-fee automated protocols become a larger part of the business—though the impact was partially offset by a higher duration of bonds traded in the U.S. high-grade sector.