The index closed 6.8 points higher after rising more than 12 points in the last two days.
Trading on the Ho Chi Minh Stock Exchange (HoSE) went up 6% to VND18.64 trillion ($792.52 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 19 tickers gain.
STB of Ho Chi Minh City-based lender Sacombank and VHM of property giant Vinhomes both closed 2% higher.
They were followed by VIB of Vietnam International Commercial Bank, up 1.8% and BID of state-owned lender BIDV, up 1.3%.
Eight blue chips fell. BCM of Becamex Investment and Industrial Development lost 1% and GVR of Vietnam Rubber Group closed 0.8% lower.
Foreign investors were net sellers to the tune of VND416 billion, mainly selling VHM and TPB of private TPBank.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list and the UPCoM-Index at the Unlisted Public Companies Market both went up 0.06%.