Binance is generally regarded as a safe cryptocurrency exchange to use, although there is one event that has damaged the exchange’s reputation for safety. In May of 2019, attackers managed to steal $40 million worth of Bitcoin from the exchange – fortunately, the exchange is sitting on a lot of capital and was able to refund all affected users in full. The exchange claims that it has drastically improved its security processes following the hack.
If the fact that Binance was hacked in the past is a deal-breaker for you, you can choose an exchange such as Kraken or Coinbase instead. However, keeping your funds on any centralized cryptocurrency exchange for a prolonged period of time comes with a considerable amount of risk.
SAFU is an insurance fund that Binance can draw from in emergency situations such as hacks. Binance says that it allocates 10% of the trading fees generated by the exchange to their insurance fund, which is secured through cold storage.