The index closed 5.95 points higher after losing 6.51 points on Tuesday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 21.39% to VND11.43 trillion ($911.08 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 15 tickers gain.
HPG of steelmaker Hoa Phat Group led with a 4.5% rise, followed by TCB of the largest private lender Techcombank, up 3.4%.
HDB of HDBank closed 3% higher and VIB of lender VIB gained 2.2%.
Six blue chips fell, with VHM of property developer Vinhomes losing 4.4%.
Foreign investors were net buyers to the tune of VND46.71 billion, mainly buying HPG and VCB of Vietcombank.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 0.56% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.03%.