You get 20 free trades to use in every fantasy game you participate in. Howver, this number can be different if this has been changed by the game owner
These trades cannot be transferred from one game to another.
There is no limit on the number of trades you can use in a week.
Once used, you can make use of the Dealer power to buy-in 3 extra trades, however, you have to loose 25 fantasy points from your team's overall fantasy points.