The index stayed in the red throughout the day, dipping to around 1,231 points in the early afternoon before climbing and ending with a near 9-point fall. This is its biggest plunge in the last seven sessions.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, rose 10 percent to VND22.4 trillion ($975 million), the highest of the past 10 sessions.
The VN30 basket, comprising the largest 30 capped stocks, saw 22 tickers in the red, with VCB of state-owned lender Vietcombank and VNM of dairy giant Vinamilk the biggest contributors to the drop of VN-Index.
VCB fell 2.3 percent. The ticker has been going sideways around the VND100,000 level since February after climbing to a new historic peak of VND107,000 in early January.
VNM dropped 2.9 percent to a nine-month low. The ticker continued its downward trend that began in January, having lost 25 percent in four months.
VHM of real estate giant Vinhomes fell 1.6 percent to its lowest level since March 30.
BID of state-owned lender BIDV lost 1.5 percent, having fallen nearly 17 percent since its mid-January peak.
On the winning side, HPG of steelmaker Hoa Phat Group rose 2.4 percent, and CTG of state-owned lender VietinBank gained, 2.1 percent. They were the top tickers pushing up the VN-Index this session.
Foreign investors were net sellers for the fifth session in a row to the tune of VND330 billion, with the strongest pressure on VPB of private lender VPBank and HPG.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 0.44 percent while the UPCoM-Index for the Unlisted Public Companies Market dropped 0.41 percent.