Pros
Cool place if you don't mind managers who give no direction or who will throw you under the bus.
Cons
Management wants an innovative, smart, high end team but puts superficial effort towards retaining high quality employees. In fact, the smart employees are the ones who decide to leave. Mediocrity thrives at Marketaxess. There is an enormous amount of turnover especially in IT (developers, business analysts). Beware about joining this place. They hate new people. There is a strata of employees who've been there for over 10 years and another one of people who've been there less than a year. The more senior people are so afraid of losing their jobs that they will make any newcomer's life miserable. The saddest part about Marketaxess is the general disrespect they have for former employees. You usually hear managers commenting about how former employees didn't know what they were doing (even interns).