The index stayed in the red for most of the day and closed nearly 21 points lower after going sideways for eight sessions.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, surged to a new peak of VND45.56 trillion ($1.98 billion).
The VN30 basket, comprising the 30 largest capped stocks, saw 22 tickers in the red, led by SSI of leading brokerage SSI Securities Corporation with a 4.1 percent drop. The third losing session in a row sent SSI to its lowest point in a month.
HDB of HDBank fell 3.8 percent in its third consecutive session in the red.
VHM of real estate giant Vinhomes and VIC of biggest private conglomerate Vingroup fell 3.7 percent and 3.6 percent respectively, pulling the VN-Index down by 7.3 points.
Other real estate stocks that fell were VRE of retail real estate arm Vincom Retail, down 1.6 percent, and NVL of real estate developer Novaland Group, down 3.2 percent.
VPB of private lender VPBank fell to its lowest in almost five months with a 3.6 percent loss.
Five blue chip tickers bucked the trend, led by CTG of state-owned lender VietinBank with a 1.7 percent gain.
VJC of budget airline Vietjet rose 1 percent.
Foreign investors were net sellers to the tune of VND626 billion with selling focus high on CEO of real estate developer CEO Group and MSN of conglomerate Masan Group.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 2.3 percent while the UPCoM-Index for the Unlisted Public Companies Market lost 1.26 percent.