China’s major state-owned banks have been buying the yuan this week, helping it recover against a lower U.S. dollar.

This is the first time such banks have done so in the past year, sometimes on behalf of Chinese monetary authorities.

The yuan has risen 2% to 7.13 to the dollar in the previous week, its strongest level in nearly four months.

State banks are exchanging yuan for dollars in the onshore swap market and selling dollars in the spot currency market.

The PBOC has also lowered the dollar-yuan daily fixing rate this week, a 3-1/2-month low.