The index closed 2.45 points higher after gaining 36.81 points on Tuesday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 13.87% to VND10.53 trillion ($447.89 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 13 tickers gained.
PLX of fuel distributor Petrolimex led with a 7% rise.
It was followed by MSN of conglomerate Masan Group, up 3.4%, and PDR of Phat Dat Real Estate Development, up 3.1%.
VPB of private lender VPBank went up 2.2%, and CTG of state-owned lender VietinBank rose 1.8%.
Thirteen blue chips fell, with NVL of property developer Novaland Group losing 4.4%, and VIC of private conglomerate Vingroup down 1.4%.
Foreign investors were net buyers to the tune of VND362.41 billion, mainly buying VPB and VRE of retail real estate arm Vincom Retail.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 0.24% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.50%.