If you're interested in the rise or fall of bitcoin you need to research the Theory of Speculation. Prices in markets move randomly. This strikes people as peculiar, as *clearly* there must be patterns, there are booms and busts after all, don't prices follow a rational logic of their own? But actually it's basically correct, asset prices do move randomly because investors/speculators change the price to fit the real circumstances. The result is that only new information (the future) affects prices, which implies you need supernatural abilities to continually predict prices. Patterns do exist in the stock market and currency markets, but you cannot consistently make profits from them because of this. Even if you don't believe it, the market behaves as if it were true.The most practical advice I can give you on buying and selling bitcoin is two words: Limit Orders. Most people appear to be using market orders, which means they are saying they want X bitcoins at any price in USD, or any number of bitcoins for X quantity of USD, which is the same thing. This ensures you get your bitcoin ASAP. The majority of market participants are inexperienced. No experienced market participant uses market orders in a volatile market, let alone one as volatile as bitcoin. This contributes to the volatility, increasing the propensity of bubble or bust like behavior.If you don't want to be out of pocket then use limit orders.A limit order, unlike a market order, isn't necessarily always filled. If prices suddenly jump and stay high then you simply don't get any bitcoins.The result is that you can specify a price for which you will not buy. So potential losses are fixed to what you can bear, which seems logical in a volatile market. The same concept applies for selling.