The first big domino to fall in the NHL trade season is the one the Bruins had been linked to the most: Bo Horvat.
The Vancouver Canucks announced on Monday afternoon that they have traded Horvat to the New York Islanders in exchange for forward Anthony Beauvillier, top prospect Aatu Raty and a conditional 2023 first-round pick.

We explored the possibility of the Bruins trading for Horvat, who currently ranks eighth in the NHL in goals with 31, a couple weeks ago. The obvious appeal is that he would have given the Bruins another impact scorer for this all-in season while also being their top center of the future if they could work out an extension.
The Islanders paid a steep price, though, and it remains to be seen if they will be able to extend Horvat.
If you're looking for a comparison of what a Bruins deal might have looked like: The first-round pick remains. Fabian Lysell is a comparable prospect to Raty, although most rankings have Raty a little higher, and the fact that Raty is a center may have appealed more to the Canucks.
For a roster player, Trent Frederic might be fairly comparable to Beauvillier, but most would probably rate Beauvillier a little more highly. For the Bruins to top the Islanders' offer, the roster player probably would had to have been Brandon Carlo, Pavel Zacha or Jake DeBrusk.
The Canucks were rumored to have some interest in Carlo, so it's possible he would have been their target. It would be tough for Sweeney to justify subtracting from his defense, though. Vancouver could have thrown in Luke Schenn, but Carlo to Schenn would still be a pretty sizable downgrade.
The Bruins would also still have to clear additional salary just to fit Horvat under the cap for this season, never mind the financial headache of fitting in another mega-contract long-term to extend him.
The good news in all of this if you're the Bruins: Horvat didn't end up with the Lightning or Hurricanes, two legitimate Eastern Conference contenders who were also rumored to be interested.
While the Islanders shouldn't be completely written off yet, they are currently 10th in the East and outside the playoff picture. Although, it's possible that if the Islanders remain out and can't get an extension done, they could turn around and trade Horvat again before March 3.
With Horvat off the market -- at least for now -- there's no other obvious comparable as far as a top center who could be extended. The Red Wings' Dylan Larkin could fit that bill if he ends up being available, but most insiders still seem to believe that Detroit will ultimately get an extension done.
The biggest names on the market now are probably San Jose Sharks winger Timo Meier and Arizona Coyotes defenseman Jakob Chychrun. If the Bruins are considering a big swing, Chychrun would probably make more sense given his position and contract situation (two years left after this at a bargain $4.6 million per year). Meier is owed a $10 million qualifying offer as a restricted free agent this offseason.