The index closed 15.31 points lower after dropping 2.73 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange increased by 78% to VND31.98 trillion ($1.3 billion).
The VN-30 basket, comprising the 30 largest capped stocks, saw 28 tickers fell.
VIC of private conglomerate Vingroup dropped 5%, followed by VRE of retail real estate arm Vincom Retail with a 3.6% decline.
VHM of property giant Vinhomes fell 3.3% and MWG of electronics retail chain Mobile World closed 2.9% lower.
Two blue chips bucked the trend. BID of state-owned lender BIDV surged 4.5% while VJC of budget airline Vietjet went up 0.2%.
Foreign investors were net seller to the tune of VND769 billion, mainly selling VPB of private lender VPBank and MWG.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 1.25%, while the UPCoM-Index for the Unlisted Public Companies Market went down 0.46%.