Have to admit I hadn't really thought about the stock market side of things. However, China is still China Inc. If you buy Chinese goods, you fund the Chinese government and military. It's been obvious for years (certainly since the Chinese were building military islands out of shoals in the S China Sea) that our imports of Chinese goods were building a military that one fine day we will have to face. So insanity is absolutely the right word, I can't even imagine what you call continuing to play the game after it became obvious. I'd probably start by labelling most of our politicians on both sides and corporate "leaders" as treasonous. There's also the part about selling US land - and unknown quantities of land adjacent to our military bases. That's nuts and treasonous.
The other thing is that US investment in China (the manufacturing plants) are always subject to being seized by China; if and when it happens, I have no sympathy at all for the companies like Apple that will see investment sunk. It's a shame that the corporate leadership (past and present) doesn't have to absorb the loss. The only saving grace is that we could turn around and seize Chinese assets here assuming we can sort out what those are because they have played games to hide Chinese ownership. Then there's the Chinese presence in our research sector and outflow of technology to use against us.
It's hard to believe that we could actually develop a policy that would make us more complicit and willing dupes than what we've just allowed to happen - what our political and business "leaders" have allowed to happen. I guess one day we'll have a populace that said "I never knew" like the Germans who "never knew" about concentration camps, gas chambers, torture ...