The benchmark VN-Index on the Ho Chi Minh Stock Exchange inched down 0.07 per cent to end at 927.25 points.
The benchmark lost 0.73 per cent on Tuesday.
More than 112 million shares were traded, worth more than VND2 trillion (US$86 million).
The figure included nearly 96 million shares traded via order-matching deals, worth nearly VND1.5 trillion.
Investors on the local market remained cautious as they worried about the new developments of Covid-19 and its impact on the global economy.
The market breadth was a bit negative with 165 declining stocks and 154 gainers.
Banking, technology, agriculture, healthcare and pharmaceuticals, seafood processing, and transportation and logistics weighed on the market.
Large-cap stocks in those sectors were tackled by strong profit taking.
The HNX-Index on the Ha Noi Stock Exchange tumbled 0.74 per cent to close at 109.26 points.
The northern market index gained 0.46 per cent on Tuesday.
More than 16 million shares were traded on the northern bourse, worth VND208 billion.
The afternoon trading session starts at 1pm.