"To lose the trade" means that someone did not make a profit or ended up with a financial disadvantage in a business transaction or deal. Full definition
It has improved my performance I started trading just three months ago and since then i was having a series of losing trades until i came across this course. (fxdayjob.com)
The key lies in losing trades properly and making sure you are trading with a strategy that is both simple and effective, like price action. (learntotradethemarket.com)