Although bitcoins are bought, sold, and lost more today than ever before, the rate of new bitcoins being created is starting to slow. The reasons behind that are a little complex, but suffice it to say, the closer we get to the 21 million maximum number of bitcoins mined, the harder it gets and we’ve just hit the 80 percent milestone.

Even if you’re only just coming to grips with this whole cryptocurrency phenomenon, or have been trading them since the days where they were worth just a few dollars each, bitcoin has been mined for far longer. Its creator, the pseudonymous Satoshi Nakamoto, mined the first bitcoin block in its blockchain back in 2009, rewarding him with 50 bitcoins. Earlier this month, miners extracted the 16,800,000th bitcoin, which is significant, because it means there are only 20 percent of all the bitcoin there will ever be to go.

The self-imposed scarcity of bitcoin is one of the reasons it has become so valuable in recent months and proponents of the flagship cryptocurrency believe that that will help propel it to new heights over the next few years. Although there are many detractors of bitcoin, claiming that its scaling issues and ballooning transaction costs make it a difficult cryptocurrency to support long-term, it has proven to be the best store of value of all 1,300-plus coins so far, as per Bitcoin.com.

Other cryptocurrencies that are in vogue, like ethereum, have no cap on their number, meaning that new Ether and similar will be produced as long as people see it as a worthwhile practice to pour their computational cycles into making it. Considering that’s also required for transactions to be completed, it’s important that it continues into the future.

As for bitcoin, as the difficulty of mining the last coins continues to increase and the rewards, in turn, are reduced, the rate of new coins being created will continue to slow. Although it’s hard to make any concrete estimations on the eventual date of the last bitcoin being mined due to the unpredictable nature of mining hardware development, some estimations put it as far in the future as the year 2140 — long after all existing investors are gone. Here’s hoping we’ve spent at least a few of our coins before then.