#数字资产生态回暖 Will Bitcoin mining really come to a stop?

When it comes to Bitcoin, many people's first reaction is "2100 million cap" and "someday it will be mined out." But actually, this understanding is a bit off. Strictly from a mathematical perspective, Bitcoin can never be fully mined—sounds a bit mystical, but the reason is actually quite simple.

It all stems from a rule that Satoshi Nakamoto embedded in the code: every 210,000 blocks, the block reward halves. Looking back at the history: starting in 2009, the reward was 50 BTC per block; in 2012, it became 25 BTC; in 2016, 12.5 BTC; in 2020, 6.25 BTC; and by 2024, it will be directly cut to 3.125 BTC. And after that? It will continue to halve.

This doesn't mean that one day there will be no rewards at all, but rather a mathematical process of infinite decay—like repeatedly pouring half of a glass of water out, with each pour getting smaller, but never completely empty. From a series perspective, this is a standard geometric series; the supply of newly created Bitcoin will become increasingly negligible, but it can never reach zero.

Another detail is that Bitcoin has a smallest unit of account called "Satoshi," which equals 0.00000001 BTC. What happens when the block reward shrinks to just 1 Satoshi? Continue halving? No, that's impossible because it can't be measured more precisely. The result is that the reward approaches zero infinitely but never actually becomes zero in name.

Considering the dimension of time, industry estimates suggest that around the year 2140, the issuance of new Bitcoin will be almost negligible. Although the ledger will still show slightly more than 21 million, the practical significance will be zero. This is also why people in the community often say that the total supply of Bitcoin is "infinitely close to 21 million" rather than "exactly 21 million"—a more scientifically precise way of describing it.

So here's the question: if the block rewards keep decreasing, why do miners still run their machines 24/7?

The answer lies in transaction fees. Every on-chain transaction requires a fee, and this money ultimately goes into miners' pockets. As block rewards diminish, miners' main income will gradually shift from "new coins" to "transaction fees." In practice, there have already been blocks where the fee income was enough to provide miners with a substantial return. In other words, the economic incentive to mine won't disappear because of halving; it just takes a different form.

Today, nearly 20 million BTC have been mined, with less than 1.3 million remaining in circulation, and this rate is slowing down. It is precisely because of this issuance mechanism, engraved in the code and stable over the long term, that Bitcoin's scarcity will continue to strengthen over time. It doesn't suddenly announce "completion" one morning, but gradually approaches that limit over a long historical process.