According to the regulatory body, two senior executives and one professional from a hedge fund are among those arrested in connection with insider deals.
The unnamed workers were taken into custody following searches in 16 locations across London, the South East and Oxfordshire.
A number of computers and documents were seized from addresses, which included both business and residential premises.
In a statement, the FSA said: âIt is believed that the city professionals passed inside information to traders (either directly or via
middlemen) who traded based on this information and have made significant profits as a result.â
The investigation is the fifth set of arrests in conjunction with insider dealing that the organisation has carried out since 2008.
A number of traders have recently been imprisoned due to their involvement in insider deals.
Malcom Calvert, Matthew and Neel Uberoi and Christopher McQuoid and James Melbourne are the individuals which have received jail sentences following an investigation by the FSA.
By Jim Ottewill