It dropped 1.66 points after losing 2.36 points on September 7.
Trading on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, gained 6.3% to 26.34 trillion VND (1.09 billion USD).
Foreign investors were net buyers to the tune of VND99 billion, mainly buying VPB of private lender VPBank and VNM of dairy giant Vinamilk.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, was up 0.02% while the UPCoM-Index for the Unlisted Public Companies Market also closed 0.02% higher.