It's called mark to maket accounting, for example suppose I have 2 Bitcoin and will like to know what is their value, I see the market price and multiply by wha

It's called mark to maket accounting, for example suppose I have 2 Bitcoin and will like to know what is their value, I see the market price and multiply by what I have, like you said. This is why people say that the current amount of bitcoin multiplied by their value makes more than $1 billion dollars. EDIT: Of course, you can't sell it all by the current market price since supply will be then much higher than demand and price will go down