Russia recently dumped the majority of its UST, widely believed to cause the treasury rate to hit 3%. Some commentators speculated the reason for this was
1) to avoid future potential sanctions
2) a trial-run to gauge how the market would react to a similar move by China.
At its peak Russia held less than $0.2T, Russia liquidated approx $50B per month for 3 months. If China dumped $75B per month for 6 months, there would be pain that would likely spread into corporate bonds.
https://money.cnn.com/2018/07/30/investing/russia-us-debt-tr...
https://www.bloomberg.com/view/articles/2018-10-16/russia-s-...
(edit: formatting)