How many #BTC have been lost?

As of October 31, 2023, approximately 19 million bitcoins have been mined, with a total supply of 21 million bitcoins that can ever exist. However, it is estimated that roughly 4 million bitcoins have been lost forever. This means that approximately 20% of all bitcoins in existence are unrecoverable.

There are a number of reasons why bitcoins can be lost. Some of the most common reasons include:

1. Lost or forgotten private keys:  If a private key is lost or forgotten, the bitcoins associated with that key are effectively lost forever.
2. Hardware failure: If a hard drive or other storage device containing bitcoins fails, the bitcoins may be lost.

3. Scams and theft: There have been a number of scams and thefts in which bitcoins have been stolen from users.

4. Human error: Bitcoins can be lost due to human error, such as accidentally sending bitcoins to the wrong address that does not exist.

The loss of bitcoins can have a significant impact on the Bitcoin ecosystem. Lost bitcoins cannot be re-mined, meaning that the total supply of bitcoins will eventually decrease. This could lead to increased demand and higher prices for bitcoins.

There are a number of things that users can do to protect their bitcoins from being lost. These include:

1. Storing private keys securely: Private keys should be stored in a safe and secure location, such as a hardware wallet or a paper wallet.

2. Backing up private keys: Private keys should be backed up regularly in case of hardware failure or other loss.

3. Being aware of scams and theft: Users should be aware of common scams and theft methods and take steps to protect their bitcoins.

4. Using reputable exchanges and wallets: Users should only use reputable exchanges and wallets to store and trade bitcoins.