Like I said "partly" responsible. Measures that he could have done that could have slowed the fall, like early quarantines, testing and so on could have alleviated the fall.Nah, come on man, this is a worldwide phenomena. If it was just in America you might have a case to make, but as is unless Trump secretly created and released Corona, the level of market devastation can't be laid at Trump's feet. Don't get me wrong though, the market will react to how he handles the situation (testing kits, etc.) as well but the magnitude of this collapse is not Trump's fault.
But, if Trump wants full credit for gains (even though he is also only partly responsible) then he must take credit for the falls. HE established these rules. Live by the sword, then die by the sword.