I know it is a tricky question. What do you think, how many Bitcoins are lost forever and are 'out of the network' by lost private keys?
I guess its too big, large number of bitcoin now for sure but I think the only one that can know that is the developer or the bitcoin founders.
I agree, it is big amount of bitcoin lost forever and still counting on that, many bitcoin just burned and lost and just gone.
And for sure no one can say this on how many where lost unless the developers got their details on this but I guess they have this like those frozen account which not is used for almost a year.
i think that it is not so easy t estimate that how many bitcoins have lost for ever. but it is a fact that there must lot of bitcoin lost, as some people may die and their wallet keys will be lost for ever, while other people my have lost their wallets keys for every. anyhow still a lot of bitcoin may be lost for every but i think no one know the fact about that.