The index closed 1.75 points lower after losing 0.45 points on June 15.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 69% to VND22.43 trillion ($953.35 million), highest in six sessions.
The VN-30 basket, comprising the 30 largest capped stocks, saw 20 tickers fall.
Foreign investors were net buyers to the tune of VND466.00 billion, mainly buying VND of brokerage VNDirect and HPG of steelmaker Hoa Phat Group.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 0.47% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.08%.
