Sometimes newbies can misunderstand the deflation that exists in
BTC. My bros once asked me that he saw information on the internet that said
BTC was deflationary, he continued the conversation by concluding the
BTC supply could decrease, like 21,000,000 to 20,000,000 someday. I then responded by saying that his understanding was wrong,
BTC deflation is not like classical economic theory, deflation in
BTC refers to its design, 3 examples are:
(1) Limited supply.
(2) Inflation level is getting lower & lower over time.

(3) Possible shrinkage of effective supply.
Estimating the Number of Lost Bitcoin
As of early 2025, analysts estimate that between 2.3 million and 3.7 million Bitcoins are permanently lost, (Source: Chainalysis), representing approximately 11–18% of Bitcoin’s fixed maximum supply of 21 million coins, with some reports suggesting losses as high as 4 million BTC (Source: Fortune). This impacts the effective circulating supply—while the total mined Bitcoin stands at around 19.8 million BTC, the usable amount is closer to 15.8–17.5 million BTC after accounting for these losses, highlighting a significant reduction in accessible coins despite the unchanged maximum supply of 21 million BTC.