The index was in the green most of the day and closed with a 2-point gain, its eighth consecutive rising session.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 1 percent to VND21.28 trillion ($926 million).
Foreign investors were net buyers for the fourth session in a row to the tune of VND830 billion, highest since July 12. They focused on VHM of real estate giant Vinhomes and STB of Ho Chi Minh City-based lender Sacombank.
The VN30 basket, comprising the 30 largest capped stocks, saw 15 tickers in the green led by STB with a 2.9 percent gain.
The ticker has experienced an upward trend in the last two weeks, having gained 11 percent.
It was followed by BVH of insurance company Bao Viet Holdings with a 2.1 percent increase, its fifth straight gaining session. It is now at a four-week high.
PLX of fuel distributor Petrolimex also rose 2.1 percent, while NVL of real estate developer Novaland Group closed 1.9 percent higher.
On the losing side, VRE of retail real estate arm Vincom Retail dropped 1.4 percent, while MSN of conglomerate Masan Group fell 1.3 percent.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.28 percent while the UPCoM-Index for the Unlisted Public Companies Market dropped 0.08 percent.