 Damianos asks, Bitcoin after the year 2140, what will happen when the network reaches block 6,930,000? Can we have Bitcoin transactions after that point? And why? And there's a lot of follow-up questions on this topic. It's a very common topic that a lot of people have confusion about. And you're giving me an opportunity to answer that, so great. George follows with, how will the miners be incentivized that if there are no block subsidies available? Dimitri asks, the miners also collect transaction fees from all of the transactions. Theoretically, by that time, transaction fees will be sufficient given the amount of transactions and the adoption of Bitcoin. Will it be sufficient though? Diva asks, 2020 is a time when miners will only get six and a quarter bitcoins for their work. Is there a possibility that miners will stop mining? In that case, who ensures the correctness of transactions? This is a question that comes up a lot, which is what happens at this far moment in the future when the block subsidy goes from one Satoshi per block to zero Satoshi per block and there is no longer any more Bitcoin being issued as a block subsidy. What you have to understand is that the question of whether miners will continue to mine is a question that occurs every single day for every single miner. And it occurs within every single mining farm at a different level, depending on the efficiency of the equipment. This is a question that is answered based on a very large set of variables that a miner has to take into consideration. Nothing special happens in this sudden moment of block 6,930,000 that didn't happen a block before, or 10 blocks before, or 100 blocks before, or 1,000 blocks before. In fact, today miners decided whether they should turn off some of their equipment, or whether they should turn on some new equipment. They're mining A6, the mining hardware that they use to mine. This is a bit like your 18th birthday. A lot of changes over midnight on your 18th birthday suddenly legally become an adult. But does that mean that in the one minute before midnight to the one minute after midnight, you became suddenly a different person and started behaving like a mature adult? For many people that never happens, but for most people this is a gradual process. There's no magic moment where things happen suddenly. Bitcoin mining is a very complex dynamic economy that depends on a very large number of variables, all of which interact in order to give each miner a profitability for each piece of ASIC mining equipment they have in their warehouse, and therefore decide on a daily basis based on their profitability and projected profitability that they anticipate over the next few days, week, months, whether they will keep running that particular piece of equipment, that ASIC mining hardware, for today. In order to make that decision, these factors include how efficient the ASIC hardware is, and this may differ from piece of equipment to piece of equipment. Imagine a warehouse with a thousand ASIC miners in it, and some of them are the current generation most efficient systems, but some of them are older generation maybe, or a couple of generations older. So, if the most efficient miner is profitable today, but the least efficient miner they have in the warehouse is not profitable today, they have the choice to turn off the least efficient miner. However, in many cases, because they've already pre-purchased electricity, they might decide to keep running it at a loss. This decision happens across millions of mining hardware devices every single day by thousands of miners who each decide how profitable their operation is within the constraints. To make this decision, they look at many different factors. One of those factors is block subsidy, how many Bitcoin are in each block, and while that changes every four years when it's divided in half, the miners anticipate that. They can see, they know that in the springtime of 2020, that profitability is going to change because the block subsidy is going to be divided by half. They also anticipate that the market is going to react to these changes, and that can affect the Bitcoin price. At the same time, they may have profit margin that's big enough to absorb that difference in the mining block subsidy. When they make that decision, they make it months in advance by purchasing better, more efficient mining hardware, by negotiating better rates of electricity, and by perhaps making hedging trades in the Bitcoin exchanges and open Bitcoin markets in order to accommodate that future risk. You can use futures to hedge some of that risk, too. In fact, Bitcoin futures are one of the ways miners operate. Now, you've got to imagine that at any moment in time, the price of Bitcoin in fiat, which is what miners pay electricity in fiat, but they earn their block subsidy in Bitcoin, so therefore the exchange rate really matters in terms of their profitability. The cost of electricity that they're currently paying, the efficiency of their equipment, the efficiency of their operations, their prediction and expectations of future prices, all of these things come into play every single day, so that they can decide which parts of their infrastructure are still efficient and which are not, whether they need to accelerate top grades or maybe even change some of their operating plans, and this decision happens every day. Nothing magical happens at block 6,930,000, that wasn't the same pretty much decision that happened at block earlier. And while the halving is a fairly abrupt event, because it's predicted from the very beginning of Bitcoin's operation, miners can anticipate a plan for that well in advance. We've seen in previous halvings, despite the media writing all of these scary stories about how Bitcoin is going to stop operating, etc., that in fact nothing much happened on the day of the halving, although the market did react mostly by changes in the Bitcoin price over the next few months or years. Now, keep in mind that one of the very important factors that goes into this calculation is the mining difficulty, so let's look at what happens if some of the miners find it unprofitable to continue to operate. What happens? They turn off the mining equipment that they're running. When they turn off the least efficient miners they have, or perhaps all of their miners because their electricity price is too high for their area, not all of the miners have the same profitability variables. Whilst the least efficient miners with the worst electricity costs are going to be unprofitable and turn off their equipment, the most efficient miners with better electricity costs are so profitable they're going to leave their equipment on. The hash rate in the network is going to drop, and within at most two weeks, usually less, then the difficulty will readjust. When the difficulty readjusts and effectively drops because there are less miners competing, that means that the miners who were previously barely profitable and continued to mine will now become much more profitable because the hashing difficulty dropped. They're going to get a bigger share of the mining gains. For a short period of time, blocks are going to come out more slowly. If there was, for example, a 50% reduction in the hashing power, which means a full half of all miners turned off their equipment, which is extremely unlikely, what would happen is you'd have blocks every 20 minutes instead of every 10 minutes, but only for about a week, a week and a half, and then the difficulty would retarget. Blocks would come out every 10 minutes, and any miner who stayed in the game would become much more profitable because they would effectively get twice as many blocks as the difficulty dropped by half. So the people who stick in the game make great profits in the long run. If you think about that in advance, you might realize that miners who are barely profitable or slightly unprofitable may decide to just stick in there because after all, the difficulty will get retargeted because some of their competitors who are less efficient will drop out. This market continuously churns in order to clear out the less efficient competitors and calibrate the difficulty so that miners are always barely profitable. And if that means less mining will be profitable, then less mining is profitable. And we've seen that happen again and again and again throughout the history of Bitcoin. Keep in mind, Bitcoin could run today with one-tenth of the mining power and be very, very secure without any problems. How do I know? Well, we had one-tenth of the mining power a year and a half ago. And it was very, very secure then. So nothing really happens when the block subsidy runs out. Nothing really happens when the halving happens. Nothing happens if a bunch of miners turn off their equipment other than a slight delay in block issuance, which then gets adjusted in less than two weeks by the next difficulty retarging. This is a dynamic system that is constantly adapting to change.