The formula for calculating capitalization is simple but it's easy to mislead others: multiply the number of bitcoin (or any coin altcoin) that exists at its current price.
Up to now, the market capitalization of bitcoin is about $ 260 billion, according to Coinmarketcap. That does not mean, however, that $ 260 billion is in place and will be distributed to people holding bitcoins.
Actually, when the bubble breaks and everyone wants to get out of their pocket money, the total amount of money to divide will never be greater than the total amount that was poured into the bitcoin, and that number is small. A lot, much more than the current market value.