This might look crazy, but if you think of it is a very smart move.These companies doing the ipo in the US must be crazy. The US has made it clear that they don't welcome Chinese listings. These companies will be better served by listing in Hong Kong or Shanghai instead, where politics and economy are way more stable.
1.) first they need to rush to get the money before trump can hold his pen signing to ban chinese companies ipo.
2.) the US is printing money like there is no tomorrow. most of the "stimulus" fund were obviously benefited only the rich. They threw the free money to the stock market so much that the US stock market is all time high with 30% decrease of economic output. They threw money to everything that barely make a profit, as long somebody else with free money shall buy in the future.
3.) if for example, Trump want to delist those already listed Chinese companies,
then thats a very big win with chinese companies, and the losers will be the american investors. The Chinese companies got their money without paying anything back.
So basically these Chinese companies are trying to beat those first two points and preparing to celebrate for the third point.