Sure. Here's an excerpt from this seasons news post:
"It has come to our attention that day trading has become rampant and a very common occurrence among top tier teams. While we don’t want to diminish transfer list activity, we cannot turn a blind eye to what’s happening, and have therefore decided to raise the player transfer taxes. These new taxes won’t affect normal teams much, but will make day trading much less profitable, if at all!"
This means that in order to prevent daytrading, we raised transfer taxes. Since you have a lot of transfers made and you sold players which you very recently bought, their taxes ate all of the income from their sale. Also, you can see the tax rate before you put a player on the transfer list, which in case of those two, was 100%.