Two lawyers were among several people arrested Thursday in a rapidly expanding hedge fund insider trading scandal.

Arthur J. Cutillo, 33, allegedly gave information about mergers and acquisitions he gleaned as an associate at Ropes & Gray to Jason Goldfarb, 31, an associate with the personal injury firm Brecher Fishman Pasternack Walsh Tilker & Ziegler. Prosecutors said that Mr. Goldfarb then passed the tips to the head of a ring who based trades on the information.