The index closed 2.73 points lower after dropping 0.02 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange decreased by 21% to VND17.95 trillion ($729.38 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 16 tickers fell.
HDB of HDBank fell 2.6%, followed by VCB of state-owned lender Vietcombank with a 1.9% decline.
MWG of electronics retail chain Mobile World dropped 1.7% and STB of Ho Chi Minh City-based lender Sacombank declined by 1.4%.
Thirteen blue chips gained. TCB of private lender Techcombank rose 3.3% and SHB of Saigon Hanoi Commercial Bank went up 1.7%.
Foreign investors were net sellers to the tune of VND939 billion, mainly selling HPG of steelmaker Hoa Phat Group and MWG of electronics retail chain Mobile World.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.07%, while the UPCoM-Index for the Unlisted Public Companies Market went down 0.04%.