What happens when all 21 million BTC is mined?

 

What should the miners choose to do, when all the 21 million BTC is being mined (since the launch in 2009). 

 

The creator of bitcoin, Satoshi Nakamoto created a supply cap of 21 million bitcoins. And to make the news worst for the miners, already more than 19 million bitcoins have been mined to date, leaving under a few million remaining to be mined.

What measures did Satoshi deploy on top of the 21 million capping? Satoshi deployed the concept of ‘halving’, where the reward that the miners earn decrease approximately after every 4 years or 210,000 blocks. However, the algorithm that governs Bitcoin is that approximately a new block is added to the blockchain every 10 minutes i.e., considering 1440 minutes in a day, and every new block in 10 minutes time, 144 blocks are mined in a day. And considering (till 2024) the block reward of 6.35 BTC, every day 900 (144 * 6.35) BTC is being added. With series of ‘halving’ event, for example, by 2028, only 1.5625 BTC will be rewarded for the addition of a block (instead of the current 6.25 BTC). Such measures in place and with the current schedule, mining of all 21 million BTC leaves a significant amount of time ahead. The rate at which new bitcoin are mined is geared to slow down over time.

The other measure Satoshi instituted is the “Difficulty Adjustments”.  That is, when the total hash rate in the network declines, the difficulty of mining declines as well and vice versa.

What’s the reward after 2140?

Let’s’ define ‘block reward’. ‘Block reward’ is the revenue that the miner generates after adding the block to the network and consists of ‘the newly minted bitcoin’ and the cumulative ‘transaction fees’ paid in the block. Thus, while the block subsidy gets halved every after 4 years, transaction fees do not get halved.

Thus, ‘transaction fees’ is what miners will be left with after all bitcoins are mined by 2140. That is, miners will be rewarded but only through transaction fees and not from newly minted coins. The transaction fees are designed to incentivize miners to continue processing transactions and maintaining the network’s security. Transaction fees can vary depending on factors such as transaction size and network demand; while block reward is fixed as its determined by the blockchain protocol.

Features	Block Reward	Bitcoin Transaction
Purpose	Transfer Bitcoin between users	Secure the network and process transactions
Who gets it	Sender & Receiver	Miner
Size	Varies depending on the number of inputs and outputs	Fixed at 6.25 per block (during the date of this posting)
Frequency	Constantly	Every 10 minutes

Note: From "CryptoTimes.io"

But in reality, it is never going to reach 'zero' even by 2140. Please check the table below:

Year Figure 2024 3.12500000000000000000000 2028 1.56250000000000000000000 2032 0.78125000000000000000000 2036 0.39062500000000000000000 2040 0.19531250000000000000000 2044 0.09765625000000000000000 2048 0.04882812500000000000000 2052 0.02441406250000000000000 2056 0.01220703125000000000000 2060 0.00610351562500000000000 2064 0.00305175781250000000000 2068 0.00152587890625000000000 2072 0.00076293945312500000000 2076 0.00038146972656250000000 2080 0.00019073486328125000000 2084 0.00009536743164062500000 2088 0.00004768371582031250000 2092 0.00002384185791015620000 2096 0.00001192092895507810000 2100 0.00000596046447753906000 2104 0.00000298023223876953000 2108 0.00000149011611938477000 2112 0.00000074505805969238300 2116 0.00000037252902984619100 2120 0.00000018626451492309600 2124 0.00000009313225746154790 2128 0.00000004656612873077390 2132 0.00000002328306436538700 2136 0.00000001164153218269350 2140 0.00000000582076609134674