The benchmark VN-Index on the Ho Chi Minh Stock Exchange gained 0.44 percent to 919.72 points.
It had risen 0.11 per cent to close Tuesday at 915.67 points.
According to BIDV Securities Co, the VN-Index is likely to fluctuate around 920 points in the last two sessions of the week when the current demand is not strong enough for a breakthrough.
Nearly 524 million shares were traded on the southern bourse, worth VND8.8 trillion (US$378.7 million).
Market breadth was negative with 217 losers and 187 gainers.
Strong cash flow poured into blue-chips, spurring the market’s gains, including Vingroup (VIC), Vinhomes (VHM), Vincom Retail (VRE), Vietcombank (VCB), Vinamilk (VNM), PetroVietnam Gas JSC (GAS), Sabeco (SAB) and Mobile World Group (MWG).
Some other pillar stocks were strongly hit by selling pressure, including Vietinbank (CTG), Military Bank (MBB), VPBank (VPB), Vietjet (VJC), Techcombank (TCB), SSI Securities Incorporation (SSI), the Refrigeration Electrical Engineering Corporation (REE), Hoa Phat Group (HPG), Vietnam National Petroleum Group (PLX) and FPT Corporation (FPT).
The large-cap tracker VN30-Index declined 0.06 per cent to 870.85 points with 16 of the 30 largest stocks by market value and trading liquidity dropping.
On a sector basis, 16 out of 25 sectors on the market made gains, such as retail, wholesale, insurance, real estate, healthcare, agriculture, banking, food and beverage, construction and logistics.
The losers included securities, information and technology, mining, rubber production, seafood processing and construction materials.
Foreign investors net sold VND193.04 billion on HOSE. They were net sellers on the HNX with a value of VND1.67 billion.
On the Hanoi Stock Exchange, the HNX-Index was down 1.19 per cent to close Wednesday at 136.13 points.
The northern market index had gained 0.43 per cent to close at 915.67 points.
More than 70 million shares were traded on the northern exchange, worth VND984.4 billion.