The index closed 14.1 points lower after losing 0.62 points on Thursday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) fell by 45.8% to VND6.55 trillion ($275.30 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 26 tickers dropped.
SSI of leading brokerage SSI Securities Corporation fell 3.6%.
GVR of Vietnam Rubber Group and NVL of property developer Novaland Group both lose 3.4%.
HPG of steelmaker Hoa Phat Group and PDR of Phat Dat Real Estate Development went down 3.3% and 3.2% respectively.
Three blue chips bucked the trend.
SAB of brewer Sabeco gained 1%, followed by GAS of state-owned Petrovietnam Gas, up 0.7%, and VCB of state-owned lender Vietcombank, up 0.2%.
Foreign investors were net sellers to the tune of VND219.15 billion, mainly selling VHM of property giant Vinhomes and VIC of private conglomerate Vingroup.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 0.95% while the UPCoM-Index at the Unlisted Public Companies Market was down by 0.87%.