Of course I am not surprised at this, because bitcoin is a commodity and whoever buys bitcoin is adding to the market cap. Bitcoin is bitcoin worldwide, but those banks are in various places and their operations is in fiat. Those banks can print more money, but bitcoin has limited supply of 21 million.
It will be impossible for centralized bank to have higher market cap than Bitcoin because gradually fiat is depreciating and bitcoin value appreciates, which is giving people more confidence to invest in bitcoin and abandon fiat because of lack of confidence in fiat. Banks are run by individuals, but bitcoin is decentralized.
I support this since bitcoin is being used globally, everywhere in the world. We can use Bitcoin, so we are not surprised if the market cap surpasses these banks. You know banks are using fiat, and the fact that there are some places where they will not accept fiat makes it easy for bitcoin to make it up to this market cap. The fact that I know bitcoin is digital also makes it obvious that bitcoin can definitely reach here. We all know how bitcoin started and see where it is now, so people believe that it will be more than this in the future, so before they miss out, that is why they are taking the necessary decision now.