The index closed 22.06 points higher after losing 12.67 points on Tuesday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 2.19% to VND10.68 trillion ($453.02 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 27 tickers gain.
SSI of leading brokerage SSI Securities Corporation surged 6.8%, followed by GVR of Vietnam Rubber Group with a 6.3% gain.
NVL of property developer Novaland Group went up 6.1% and VIB of Vietnam International Commercial Bank rose 5.7%.
Only three blue chips fell. VRE of retail real estate arm Vincom Retail went down 1%, GAS of state-owned Petrovietnam Gas lost 0.6% and SAB of brewer Sabeco closed 0.3% lower.
Foreign investors were net buyers for the seventh straight session to the tune of VND217.76 billion, mainly buying HPG of steelmaker Hoa Phat Group and POW of electricity producer Petrovietnam Power Corporation.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 2.20% while the UPCoM-Index at the Unlisted Public Companies Market was up by 1.08%.