All bitcoins which have been mined so far are still sitting on the blockchain at their respective addresses. And they will be there for as long as the blockchain itself exists. In this way, they are pretty indestructible. The fact is some of these bitcoins are not accessible since the keys that would allow moving them (e.g. spending) are lost for good (forgotten, destroyed, whatever), and that's what is meant by bitcoins having been lost.



do you have a backup of the private key of BTC address you bought BTCs for? basically when you buy bitcoins you give a public address to receive the coins. do you have the secret key of that BTC address you used for buying bitcoins?