One of the four, 39-year-old Samir Barai, surrendered to federal authorities and will be in court later today.
Barai, who runs Barai Capital Management, is suspected of receiving illegal tips about publicly traded companies from a technology-industry consultant.
He founded Barai Capital Management after leaving Citigroup, where he was a hedge fund manager, in 2008.
Federal investigators searched Barai's offices in November and seized recordings of telephone calls in which employees discussed inside information about tech companies with an expert-network consultant.
One of the suspects was arrested this morning.
The remaining two pleaded guilty, possibly yesterday, in a sealed courtroom in Lower Manhattan.
One of them is believed to be 38-year-old Jason Pflaum, a tech analyst believed to work for Barai.
Two of the portfolio managers were also charged with obstruction of justice.