 All right, our next question comes from Gary, a Bitcoin key metrics. Hey, aside from the interesting graphs, is there a specific purpose for including these metrics, particularly price in the course material? And just for reference, what Gary is talking about is the slide that includes the total bitcoins in circulation, the major cryptographic currencies and their names, prices, capitalization, and the overall capitalization of the Bitcoin market value, as well as the networking hashing power path. Yeah, there is a point beyond these being interesting graphs, and that's to see how certain metrics may or may not correlate with each other. So looking at, for example, hash power and then comparing that to prices is very interesting, because of course, hash power is influenced by price because it changes the economics of mining. Given that miners spend their reward to pay for electricity, and the electricity is paid for in their local currency and therefore needs to be exchanged for their local fiat currency, their dynamic economy, the economics of mining, is heavily influenced by price. Also, it's important to understand that it's not just Bitcoin, of course. There are many different cryptocurrencies and they all play different roles and have different prices and capitalization. So yeah, that's why those charts are in there. George asks, the BTC hash rate dropped 36% between the 23rd and 24th of September. How do you interpret this drop and which can be the reasons behind it? Well, first of all, it's actually very difficult to measure the hash rate over short periods of time. Some of these drops may be due to widespread electrical problems in a region where there are a lot of miners. Some could be due to various other geopolitical reasons and things like that. In this particular case, I think we found out shortly thereafter that a warehouse with over $100 million worth of equipment burned down, and as a result that hash power went offline. It was quickly replaced, and most of that recovered almost immediately because the rate of growth exceeds that quite substantially. So I think that might be one explanation. But one of the beauties of having anonymous miners that we don't know where they are and who they are, is that when you observe these things from the outside, it's difficult to pinpoint the exact cause. That actually means the counter to that, of course, is that if you don't know who the miners are, you can't coerce them, or governments can't coerce them to make them do something or not do something. So that's an advantage. These two kind of balance each other out. Eric asks, I understand that the exchange rate between Bitcoin and Fiat, or really any cryptocurrency in Fiat, is determined presently by the forces of supply and demand. However, what was the initial criteria to determine the ask price of USD in BTC terms? Well, the initial criteria to determine the ask price for USD and BTC terms was again by the forces of supply and demand. So in the first exchange that allowed people to exchange Bitcoin and Fiat, someone would have to go there and offer Bitcoin for sale and ask for a specific amount of Fiat by placing a sell order. And someone else would have had to go and place a buy order and ask for a specific amount of Bitcoin in exchange for Fiat at a specific price. And as various orders got closer and closer together between the ask and bid prices, at some point they reach equilibrium and somebody says, yes, I'll make that order. And the engine that runs the exchange does the order matching where it finds two orders where the buyer and seller agree on price. So basically the initial criteria to determine the price of any asset, but also, of course, Bitcoin in terms of any currency, were also supply and demand. You need an open market. Now, because this was an exchange between crypto and Fiat on an exchange system, that set the initial price for crypto in terms of Fiat. The first commercial transaction that we know of was in fact the famous pizza bought by Laszlo Hanyak back in 2010. And that is celebrated as a Bitcoin pizza day. And if you know that story, Laszlo paid 10,000 Bitcoin for two domino pizzas to be shipped to his house. So that established a value in terms of a real commercial transaction for actual goods, rather than simply exchanging one currency to another. So one is an exchange rate, the other one is a price, which is slightly different from an economics perspective.