The benchmark VN-Index on the Ho Chi Minh Stock Exchange increased by 0.92 per cent to close at 976.87 points.
The VN-Index was up 0.22 per cent on Tuesday.
More than 73 million shares were traded on the southern bourse, worth VND1.45 trillion (US$62.3 million).
Large-cap stocks drove the stock market in early trading.
The large-cap VN30-Index, which tracks the performance of the 30 largest stocks by market capitalisation, advanced 0.95 per cent to end at 886.64 points.
Twenty-one of the 30 stocks in the VN30 basket made gains while eight declined and only one ended flat.
The best performer of the 21 gaining blue chips was steel maker Hoa Phat (HPG), which jumped 3.6 per cent.
Other gainers included Vietinbank (CTG), Vietcombank (VCB), Techcombank (TCB) and dairy producer Vinamilk (VNM).
On a sector basis, financials and banks recovered from their previous downtrend.
Petroleum stocks extended gains on increasing oil prices in global trading.
On the Ha Noi Stock Exchange, the HNX-Index inched up 0.14 per cent to end at 106.44 points.
The northern market index was up 0.62 per cent on Tuesday.
Nearly 19 million shares were traded on the northern bourse, worth VND195 billion.
The afternoon trading session starts at 1pm.