One theory is that the virus, which occurs naturally in bats and pangolins, escaped accidentally from the Wuhan research facility because of poor safety protocols.
After all, the Wuhan Institute of Virology studies coronaviruses in bats, that is one of its jobs. And it is right next to where some of the infections were first diagnosed.
Indeed on 2 December 2019 the lab moved down the road a short way, to new premises just a few hundred meters from the wet market...was that how the virus escaped, because of China's lax safety record in its labs? Or was the lab move part of its cover-up for something it knew had gone wrong?
On reflection, why was China even studying coronaviruses? What was its purpose? Was it part of a bio warfare weapons program?