What do you mean? Yes, the last Bitcoin will get mined. There will be no more block reward, so the only mining would be from collecting transaction fees…the total number of Bitcoins that will ever exist is capped at 21 million. This is a hard limit set by the Bitcoin protocol itself. As of now, every 10 minutes, 6.25 Bitcoins are created and given as a reward to the miners. This reward halves approximately every four years in an event known as “halving”. Eventually, around the year 2140, the reward will become so small that it will effectively reach zero, and at some point, all 21 million Bitcoins will have been mined.
Divisibility allows Bitcoin transactions to continue even after the last Bitcoin has been mined, because you can still transfer a fraction of a Bitcoin. However, the divisibility of Bitcoin does not mean that mining can continue indefinitely. Once all 21 million Bitcoins have been mined, no new Bitcoins will be created. But the Bitcoin network will still need to be maintained and transactions will need to be validated. This is where transaction fees come into play. – if the network stays PoW people will have to burn electricity to collect the fees, so that could be an issue. PoS may solve this somehow? Do you believe that transaction fees will be enough to keep Zcash secure in the future?
Here is an email from Satoshi where he speaks about why he created the supply cap:
SOURCE: Satoshi Reply to Mike Hearn - Nakamoto Studies Institute
" From: Satoshi Nakamoto satoshin@gmx.com
Date: Sun, Apr 12, 2009 at 10:44 PM
To: Mike Hearn mike@plan99.net
Hi Mike,
I’m glad to answer any questions you have. If I get time, I ought to write a FAQ to supplement the paper.
There is only one global chain.
The existing Visa credit card network processes about 15 million Internet purchases per day worldwide. Bitcoin can already scale much larger than that with existing hardware for a fraction of the cost. It never really hits a scale ceiling. If you’re interested, I can go over the ways it would cope with extreme size.
By Moore’s Law, we can expect hardware speed to be 10 times faster in 5 years and 100 times faster in 10. Even if Bitcoin grows at crazy adoption rates, I think computer speeds will stay ahead of the number of transactions.
I don’t anticipate that fees will be needed anytime soon, but if it becomes too burdensome to run a node, it is possible to run a node that only processes transactions that include a transaction fee. The owner of the node would decide the minimum fee they’ll accept. Right now, such a node would get nothing, because nobody includes a fee, but if enough nodes did that, then users would get faster acceptance if they include a fee, or slower if they don’t. The fee the market would settle on should be minimal. If a node requires a higher fee, that node would be passing up all transactions with lower fees. It could do more volume and probably make more money by processing as many paying transactions as it can. The transition is not controlled by some human in charge of the system though, just individuals reacting on their own to market forces.
Eventually, most nodes may be run by specialists with multiple GPU cards. For now, it’s nice that anyone with a PC can play without worrying about what video card they have, and hopefully it’ll stay that way for a while. More computers are shipping with fairly decent GPUs these days, so maybe later we’ll transition to that.
A key aspect of Bitcoin is that the security of the network grows as the size of the network and the amount of value that needs to be protected grows. The down side is that it’s vulnerable at the beginning when it’s small, although the value that could be stolen should always be smaller than the amount of effort required to steal it. If someone has other motives to prove a point, they’ll just be proving a point I already concede.
My choice for the number of coins and distribution schedule was an educated guess. It was a difficult choice, because once the network is going it’s locked in and we’re stuck with it. I wanted to pick something that would make prices similar to existing currencies, but without knowing the future, that’s very hard. I ended up picking something in the middle. If Bitcoin remains a small niche, it’ll be worth less per unit than existing currencies. If you imagine it being used for some fraction of world commerce, then there’s only going to be 21 million coins for the whole world, so it would be worth much more per unit. Values are 64-bit integers with 8 decimal places, so 1 coin is represented internally as 100000000. There’s plenty of granularity if typical prices become small. For example, if 0.001 is worth 1 Euro, then it might be easier to change where the decimal point is displayed, so if you had 1 Bitcoin it’s now displayed as 1000, and 0.001 is displayed as 1.
Ripple is interesting in that it’s the only other system that does something with trust besides concentrate it into a central server.
Satoshi"