What caused the Coronavirus?

It is theorized the virus mutated from somewhere and infected a bat. In Wuhan the people hunt  and eat the wildlife, this meant that someone unknowingly ate the infected bat and due to the nature of the virus, spread it unknowingly. This initial spread showed that the virus had a high rate of infection allowing it to reach a lot of people. There is a 2 week period were a person with the virus is infectious but doesn't know it which is why it spread so fast. I believe that it has mutated at least 2 more times since it's initial discovery. I hope this help a little.