People's Bank of China set the onshore yuan (CNY) reference rate for the trading session ahead.

USD/CNY is the onshore yuan. Its permitted to trade plus or minus 2% from this daily reference rate.
CNH is the offshore yuan. USD /CNH has no restrictions on its trading range.
A significantly stronger or weaker rate than expected is typically considered a signal from the PBOC.
The previous close was 6.8966

PBoC injects 2bn yuan of 7-day reverse repos at an unchanged rate of 2.0%

358bn yuan of RRs mature today

thus net drain of 356bn yuan on the day