The index closed 7 points higher after rising 20.5 points Monday.
Trading on the Ho Chi Minh Stock Exchange, on which the index is based, fell 12% to VND18.4 trillion ($724 million).
The VN30 basket, comprising the 30 largest capped stocks, saw 16 tickers in the green.
PLX of fuel distributor Petrolimex led with a 5.4% rise, followed by VJC of budget airline Vietjet, up 4.6%.
VNM of dairy giant Vinamilk gained 3.3% and FPT of IT giant FPT Corporation closed 2.9% higher.
Ten blue chips fell. CTG of state-owned lender VietinBank dropped 1.2% and BID of state-owned lender BIDV fell 1%.
Foreign investors were net buyers for the third session in a row to the tune of VND120 billion, mainly buying HPG of steelmaker Hoa Phat Group and MWG of electronics retail chain Mobile World.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.29% while the UPCoM-Index for the Unlisted Public Companies Market gained 0.50%.