Search warrants were executed at four addresses in London as part of the operation.
All three were interviewed under caution and then released on police bail.
The operation was jointly carried out by the FSA and the City of London Police Economic Crime Directorate.
The FSA says no further details can be confirmed at this time and the investigation continues.
This is the fourth set of arrests carried out by the FSA and the City of London Police in regards to insider dealing since 2008.