Today is Bitcoin Infinity Day: ∞/21M on 8/21! The date 8/21 represents the hard cap of 21 million bitcoin -- the immutable supply limit coded into the protocol by Satoshi Nakamoto. While fiat currencies can be printed infinitely, Bitcoin's scarcity is absolute and enforced by every node on the network. The ratio of infinite demand to finite supply (∞/21M) captures why Bitcoiners see it as the hardest money ever created. Celebrated annually by the community as a reminder of what makes Bitcoin fundamentally different.
Bitcoin Wiki: Controlled supply (21 million cap)