Bitcoin is about to reach the milestone of 20 million BTC mined in mid-March, with only 1 million left to be mined but still accessible for 120 years. This article details Satoshi Nakamoto’s deflationary design, the disappeared 4 million coins, and the scarcity economics of the institutional era.
(Background: Who killed Bitcoin? The record-breaking sell-off of BTC ETFs and the deleveraging chain reaction (deep analysis))
(Additional context: Female investor Cathie Wood: Bitcoin is “undoubtedly” superior to gold and has more structural advantages in the modern financial system)
Table of Contents
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- Bitcoin Halving Mechanism
- The Disappeared 4 Million Coins
- Who Owns the Last Million
- The Promise of 2140
Since Bitcoin’s first block was created on January 3, 2009, countless miracles have been written. By mid-March 2026, the Bitcoin network will have mined around block height 940,217, reaching the 20 million BTC milestone.
This means that, within the hard cap of 21 million coins, over 95% will soon be in circulation. But you don’t need to worry about the remaining 1 million being mined quickly and affecting network security, because under current rules, it will take approximately 120 years to mine all BTC.
Bitcoin Halving Mechanism
To understand why the 21 millionth Bitcoin won’t be mined until around 2040, you need to understand Bitcoin’s issuance mechanism.
In 2009, the Bitcoin network launched. For each block mined, miners receive 50 BTC as a reward. Every 210,000 blocks (roughly four years), this reward automatically halves. No exceptions, no negotiations.
So far, there have been four halvings:
- November 2012: 50 BTC halved to 25 BTC
- July 2016: 25 BTC halved to 12.5 BTC
- May 2020: 12.5 BTC halved to 6.25 BTC
- April 20, 2024: Block height 840,000, halving again: 6.25 BTC to 3.125 BTC
In plain language, today, mining one block yields only 6.25 BTC, down from 50 BTC in 2009.
The next halving is expected around 2028, reducing the reward to 1.5625 BTC. The following one will be in 2032, at 0.78125 BTC. This decreasing pattern continues until around 2140, when the last Bitcoin is mined and block rewards reach zero.
Currently, the block height is approaching 940,000. There are about two weeks left until the 20 millionth Bitcoin is mined.
The Disappeared 4 Million Coins
Another often overlooked fact is that, although 20 million Bitcoins are about to be mined, this does not mean that 20 million coins truly “exist.”
According to on-chain analysis firms like Chainalysis and River Financial, approximately 3 to 4 million Bitcoins have been permanently lost. The reasons vary: early miners forgetting private keys, hard drives discarded, wallets with forgotten passwords. These coins still exist on the blockchain but are no longer accessible.
The largest “sleeping asset” among these is believed to be Satoshi Nakamoto’s holdings.
Between 2009 and 2010, Satoshi mined about 1 million BTC. These coins have never moved since. No one knows who Satoshi is, whether they are still alive, or if they still hold the private keys. But the blockchain faithfully records everything: these 1 million BTC quietly sit in the earliest thousands of blocks, becoming the world’s largest digital legacy.
Subtracting the lost coins, the “effective circulating supply” of Bitcoin is roughly between 15.8 million and 17.5 million.
In simple terms, the actual tradable Bitcoin in the market might be 20% less than you think. Based on this, the annual new issuance is about 164,000 BTC (3.125 BTC per block × approximately 52,560 blocks per year). After the 2028 halving, this number will be cut in half again.
Who Owns the Last Million
If the story of the first 20 million Bitcoins is “who mined them first,” then the story of the last 1 million will be “who can hold on until the end.”
In January 2024, the U.S. Securities and Exchange Commission approved the first spot Bitcoin ETFs. BlackRock’s iShares Bitcoin Trust (IBIT) accumulated over $54 billion in assets within a year, holding about 786,000 BTC. Along with Fidelity’s FBTC ($12 billion) and Grayscale’s GBTC ($10.8 billion), U.S. ETFs alone hold over 1 million BTC.
Grayscale’s 2026 Digital Asset Outlook predicts that the assets under management in crypto ETFs will surpass $400 billion by 2026. If this forecast proves true, institutional holdings could account for over 15% of the effective circulating supply.
In traditional finance, the scarcity of gold depends on limited reserves in the Earth’s crust and marginal extraction costs. Yet, about 3,500 tons of new gold are mined annually, accounting for 1.5% of the above-ground stock. Bitcoin’s annual issuance is already below 0.8% of its total supply and continues to decline.
Bitcoin’s scarcity is being validated by the largest asset managers, sophisticated quant funds, and even sovereign investors, who are voting with real money.
The Promise of 2140
Returning to the initial question: what does the 20 millionth Bitcoin mean?
It signifies a 17-year-old network that has so far perfectly executed its issuance promise. No delays, no modifications, no “temporary adjustments under special circumstances.” Four halvings, precisely on schedule.
In a world where central banks can decide to print $2 trillion overnight in emergency meetings, this mechanical predictability itself is a form of scarce resource.
But the real test of Bitcoin is not today, but in the future. When block rewards approach zero, when transaction fees must alone support network security, and when the last Bitcoin is mined around 2140, will Satoshi’s original time equation—written in 2008—continue to operate?
No one can answer this question precisely, because its timespan exceeds any individual’s lifespan. But perhaps this is the essence of Satoshi’s design: he didn’t hand Bitcoin over to anyone; he handed it to time.
And time is the only judge in this universe that accepts no bribes.
