Is it common to trade players amongst college summer league teams? Or do the rosters, once formed, stay pretty solid?

.
Haven't heard of trades...

...but in our experience the stability of the rosters really depends upon the club and the league...(ours have played a total of 5 summers with 4 different teams, in 4 different leagues)...

...generally they are quite stable but there can be some turnover as the season progresses...injuries suffered, injuries recovered from, finances, playing time, summer school all have a role to play. Last year we lost players to DI football practice starting. Pitchers seem to be in demand season long and may be signed in mid season..

...given the new academic rules...I would expect summer school to play a greater role.

...Also teams going to the NBC World Series often "load up" their rosters prior to the event...

44
.