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But if we add bitcoins on centralised crypto exchanges to this statistic, we can get a figure = 31%. This is good news as more bitcoins come out of the shadows. But in my opinion if you take into account lost coins permanently, at least 30% of coins will be in the shadow zone.
But how are they coming up with these numbers for lost coins permanently? Frankly, the numbers vary widely. It is a huge difference whether 2 million BTC or 6 million BTC are lost.
Bitcoins lost forever 2.4m (11%), according to report an estimate suggest between three million to as many as six million may be have been lost forever.
A loose estimate that's often agreed upon is 3.5 million.
I searched for sources for a while now and I agree that what shahzadafzal said. It ranges from sometimes 1.8m to as many as 6 million. Does anyone know a source of which you think the applied methodology to determine lost coins permanently makes sense and is verifiable to a certain degree?
Since these sources vary so widely, I think nobody really has a clue as to how many BTC are lost. When a guy says he threw a hard drive in the trash, even that can't be verified. It is probably true, but it doesn't have to be. Are satoshis coins considered lost permanently in most of these reports?
It can't be solely based on peoples' reports or coin age.