I monitor bitcoin price every day and analyze how it goes up and down. One thing that interests me is that sometimes it seems there is a force against price fall that resists against falling below a certain price level. For example, since yesterday, I have seen that bitcoin price tried to remain about $8700 and withstood against going lower than that. Is there a group of traders who can control bitcoin price and support it to stay at a certain price? How is this possible when so many people buy and sell bitcoin from all over the world? I don't think all people have agreed upon $8700 as a resistance level.