The index closed 6.31 points lower after gaining 11.72 points on Thursday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 3.8% percent to VND16.08 trillion ($686.74 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 22 tickers dropped.
SSI of leading brokerage SSI Securities Corporation fell 2.7%.
STB of Ho Chi Minh City-based lender Sacombank lost 2.1% and HPG of steelmaker Hoa Phat Group fell 1.5%.
TPB of private TPBank and VIC of biggest private conglomerate Vingroup both fell 1.4%.
Seven blue chips gained, led by MWG of electronics retail chain Mobile World with a 5.6% rise.
POW of electricity producer Petrovietnam Power Corporation fell 1.1%, and FPT of IT giant FPT Corporation fell 1%.
Foreign investors were net sellers to the tune of VND61.59 billion, mainly selling VIC of biggest private conglomerate Vingroup and EIB of private lender Eximbank.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 0.78% while the UPCoM-Index at the Unlisted Public Companies Market was down by 0.76%.