Between them, Fitzpatrick adn Machado have more than 35 years' experience in data, financial technology and trading.
Stuart Connolly is replacing Sjöberg.
Jenny Knott says being agnostic is necessary to adapt to emerging technologies.
The deal follows previous investments made by Icap and its financial technology incubator, Euclid Opportunities.
Firm's PTRI division partners with blockchain fintech vendor Axoni.