The index closed 4.60 points lower after dropping 6.32 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange decreased by 28% to VND18.740 trillion (US$736.3 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 18 tickers fell.
GVR of Vietnam Rubber Group lost 2.4%, SAB of brewer Sabeco dropped 1.7% and VCB of state-owned lender Vietcombank closed 1.6% lower.
Nine blue chips gained. MWG of electronics retail chain Mobile Worldup went up 1.3%, followed by HPG of steelmaker Hoa Phat Group with a 1.2% growth and VIC of private conglomerate Vingroup, up 0.9%.
Foreign investors were net seller to the tune of VND1.4 trillion, mainly selling VHM of property giant Vinhomes and VCB of Vietcombank.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 0.38%, while the UPCoM-Index for the Unlisted Public Companies Market went up 0.07%.