How many bitcoins do you think have been lost forever?
I personally think its around 3 to 4 million.
i dont know the fixed number maybe arround 2m I personally think its around 3 to 4 million.
but i know some burning address, sometimes i think wanna use supercomputer to decode the private key, then i can use thats bitcoin
this is some burning address
https://blockchain.info/address/1CounterpartyXXXXXXXXXXXXXXXUWLpVr
https://blockchain.info/address/1BitcoinEaterAddressDontSendf59kuE
https://blockchain.info/address/1111111111111111111114oLvT2