I'm wondering what could've lead Binance Coin towards new heights within such a short amount of time? Does the "De-Fi" hype have to do anything about this? Do you think BNB's current prices are sustainable or not? Your input will be greatly appreciated. Thanks. 
Yes definitely defi triggers the bnb price too. But from what I remembered they are started to pump before their IEO launchpad of safepal. This is due to the changes of the IEO mechanics which changed from lottery to accumulation of bnb the many you hold the more chances to get the token on your allocation. Also this period start or marked the trending of BSC due to gas price of eth network. People transfer from those aching fees to bsc network due to those small fee on Binance.