The spot market opened at 6.4566 per dollar, surged to a high of 6.4138 at one point before changing hands at 6.4417 per dollar by the 0830 GMT domestic close, the strongest since Dec. 10, 2015.

If the yuan closes at the level in the night trading session, it would have gained around 0.38 percent from the previous late night close of 6.4665 per dollar last Friday.

Its offshore counterpart, mostly traded in Hong Kong, jumped as high as 6.4155 per dollar, its firmest since Nov. 25 2015, before trading at 6.4450 as of 0830 GMT.