You are thinking about what is logically efficient, but the market is also concerned about what is emotionally efficient.
A certain proportion of people believe climate change is a hoax, a certain proportion stand to make a lot of money shaping policy as if it were a hoax. With the coronavirus, merited or not the panic is real and the markets are reflecting that panic.
In a world economy driven by consumer spending, how people feel is more real than what is actually real for the market. Therefore, the market is always at its most efficient.
A certain proportion of people believe climate change is a hoax, a certain proportion stand to make a lot of money shaping policy as if it were a hoax. With the coronavirus, merited or not the panic is real and the markets are reflecting that panic.
In a world economy driven by consumer spending, how people feel is more real than what is actually real for the market. Therefore, the market is always at its most efficient.