20 10 before March, the only way to get bitcoin besides mining is to go to the forum for trading. There was no cryptocurrency exchange before this. Forum refers to a platform for btc enthusiasts (abroad) to learn and discuss. Some people also posted information about selling btc on the forum, but few people bought it at that time, because btc was really worthless at that time and its circulation was relatively small. The second method may be what you said, private transactions between enthusiasts or collectors and miners. Because btc's initial algorithm is relatively simple and the cost of mining is very low, Dell computer is used for the initial mining. I hope to adopt it, but I can believe it privately if I don't understand it.