The index closed 6.35 points higher after gaining 10.38 points on Tuesday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 8.10% to VND15.20 trillion ($647.29 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 18 tickers gain.
VNM of dairy giant Vinamilk led with a 2.5% rise.
VCB of state-owned lender Vietcombank gained 2.2%, and STB of Ho Chi Minh City-based lender Sacombank 1.6%.
Other gainers included TCB of the largest private lender Techcombank, 1.2%, and NVL of real estate developer Novaland Group, 1.1%.
Twelve blue chips fell, with SAB of brewer Sabeco losing 1.6%, and VRE of retail real estate arm Vincom Retail falling 0.9%.
Foreign investors were net sellers for the fourth straight session to the tune of VND162 billion.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 0.72% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.56%.