We all know Bitcoin is scarce. There will only ever be 21 million of them, no more, no less. But here’s the question a lot of people don’t really think about: what happens when we finally mine the very last Bitcoin?

If everything goes as designed, that’ll be around the year 2140. That’s way beyond our lifetime, but it’s still a big deal because the system is already moving towards that point. Right now, miners keep the Bitcoin network secure by confirming transactions and getting rewarded with new bitcoins. That’s called the block reward. But every four years, the reward gets cut in half, the famous halving. Over time, those rewards get so small that eventually, they disappear.

When that happens, miners won’t earn new bitcoins anymore. Instead, they’ll get paid through transaction fees, the small amounts we pay whenever we send Bitcoin from one wallet to another. The idea is that those fees will be enough to keep miners working, which keeps the network running. But here’s where it gets interesting: will transaction fees alone be enough to keep things secure? If fees are too low, some miners might drop out, and that could make the network weaker. If they’re high enough, the system could keep running strong.

In my view, Bitcoin won’t just collapse after 2140. By that time, it could be deeply integrated into the global economy, maybe even more than gold is today. Mining technology might be completely different, and the big players, whether they’re governments, institutions, or massive holders, will have every reason to keep the network alive and secure. The fixed supply is part of what gives Bitcoin its value. When the last one is mined, it won’t be the end, it’ll be the start of Bitcoin’s “pure” phase, where the network survives solely on transaction activity. That’s when we’ll see if it can truly function as a permanent, decentralized money system. Personally, I think it will. The incentives to protect something that valuable will still be there — just in a different form.