I think it would be very helpful to add what a watched trade was bought out for to the notification message.

Currently, we only recieve a message that someone bought out a trade we are watching. But some of us may watch trades to see offers and get a sense for what something is currently going for on the market. Sometimes we forget what a trade's buyout was though, or didn't catch what the "winning" offer was. Other times we may be watching several similar trades and have a hard time remembering the differences, but the amount might jog our memory. Adding this information to the notification message would help.
For example:
"The trade (insert trade name) you were watching was bought out for 100 SB."

"The trade (insert trade name) you were watching was bought with the offer of 1 lion."