The index closed 6.02 points lower after gaining 16.83 points on Thursday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 10.06% to VND20.33 trillion ($846.91 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 23 tickers dropped.
VHM of property giant Vinhomes dropped 2.3%, followed by CTG of state-owned lender VietinBank with a 1.9% decline.
VPB of private lender VPBank closed 1.5% lower and STB of Ho Chi Minh City-based lender Sacombank dropped 1.4%.
Seven blue chips gained, led by SAB of brewer Sabeco with a 1.8% rise.
Foreign investors were net sellers to the tune of VND849.58 billion, mainly selling CTG and MWG of electronics retail chain Mobile World.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 0.14% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.18%.