>What I don't get, is how do these prices actually change? For btc or a stock. Easy, so take a look at this which was linked upthread: https://www.gdax.com/tra

>What I don't get, is how do these prices actually change? For btc or a stock. Easy, so take a look at this which was linked upthread: https://www.gdax.com/trade/BTC-USD https://www.gdax.com/trade/BTC-USD So the weird moving green and orange bars in the middle of the screen are the order book. Green is the 'buy' side of the book and orange is 'sell.' Buy and sell orders get matched, the sale goes through and both the buy and sell order disappear from the order book. If there's more demand to buy then the green bar starts eating into the orange section and pushes the price up. Vice versa in a crash, and it works the same way for stocks. And you can see that the orange and green sections are cumulative. So if the price right now is $12000 I can scroll over $12,250 and it'll say something like 280 BTC, that number is how many bitcoins I have to buy to eat the order book up to $12,250 (which makes that the new price).