The index closed 22.67 points lower after dropping 0.93 points on Tuesday.
Trading on the Ho Chi Minh Stock Exchange decreased by 37% to VND19.106 trillion (US$751.6 billion).
The VN-30 basket, comprising the 30 largest capped stocks, saw 26 tickers fell.
GVR of Vietnam Rubber Group slid 5.6%, BID of state-owned lender BIDV went down 4.4%, and CTG of lender VietinBank closed 4.0% lower.
Four bluechips gained. MSN of conglomerate Masan Group grew 1.1%, POW of electricity producer Petrovietnam Power Corporation saw a 0.5% uptick, and VNM of dairy giant Vinamilk went up 0.3%.
Foreign investors were net seller to the tune of VND987 billion, mainly selling FUEVFVND of exchange-traded fund DCVFMVN DIAMOND and MBB of lender MB Bank.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 1.15%, while the UPCoM-Index for the Unlisted Public Companies Market went down 0.55%.