‘Zoonotic’ viruses are pretty well known.
That’s the term for viruses that jump from other species to humans.
But how did it jump from a distant cave to Wuhan? Horseshoe bats aren’t sold in the wet markets. The cave where the horseshoe bats live is hidden...and a long distance from where the outbreak began.
One possible explanation was that a researcher was somehow infected in the cave, and brought the virus back to Wuhan with them. But no one has suggested that yet.