The index closed 3.51 points lower after gaining 4.94 points on July 26.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 26.43% to VND22.70 trillion ($959.14 million).
Foreign investors were net buyers to the tune of VND329.94 billion, mainly buying VNM of dairy giant Vinamilk and VHM.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 0.24% while the UPCoM-Index at the Unlisted Public Companies Market gained 0.05%.
