It’s possible that as much as 20% of all bitcoin is irrecoverably lost.
Discussion
"Lost coins only make everyone else's coins worth slightly more. Think of it as a donation to everyone."
- Satoshi Nakamoto
I think it’s likely, and that 20% is low. In the early days there was a lot of careless loss. I lost my password at one point and had to pay some dude called BitcoinDave 15% of my holdings to recover it. He was successful, and true to his word returned 85%. What was the 15% worth at the peak? Yeah. He’s not worrying about money. This was 2010. Anyway, I digress. I think the current valuation is grossly underestimating the total supply.