Changxin just became very profitable, due to high DRAM prices. They're planning an IPO. And, of course, building more fabs. Yangtze Memory Technologies isn't as far along, but they're building a new fab and planning an IPO.
Both of these companies were created in 2016 as part of a national effort to become a force in the DRAM industry. It took a while to get the technology working. Now it works, and they can scale up.
[1] https://chinabizinsider.com/how-the-economics-of-the-global-...