Berard, 23, was a fifth-round pick of the Rangers in the 2020 NHL draft. He spent most of last season split between New York and AHL Hartford, scoring six goals and 22 points in 41 games played with the Wolf Pack and complining six penalty minutes in 13 opportunities with the Rangers.
Trudeau, meanwhile, was a fourth-round pick of the Canadiens in 2021. The 23-year-old has yet to make his NHL debut, but he tallied eight goals, 20 points and 54 penalty minutes in 62 games with AHL Laval last season.
The trade comes just hours before the start of the 2026 NHL Draft (Sportsnet, Sportsnet+, 6:30 p.m. ET / 3:30 p.m. PT).
The Canadiens have the 28th pick, while the Rangers own the fifth and 26th selections.