On the 3rd of July, 2018, Binance announced the Secure Asset Fund for Users (SAFU) as an emergency insurance fund to protect their users in the event of any hacks or security breaches.
The SAFU fund is collected as a portion of users' trading fees, and increases as more users trade on Binance
gm is the short form writing for good morning. Used extensively within the crypto community where individuals greet each other casually. On the other hand, good night (gn) is used when people sign off for the day.