The index closed 6.8 points higher after gaining 2.5 points Monday.
Trading on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 12% to VND14.88 trillion ($616.66 million).
The VN30 basket, comprising the 30 largest capped stocks, saw 22 tickers gained.
BID of state-owned lender BIDV led with a 1.9% increase, followed by MSN of conglomerate Masan Group, up 1.6%.
HPG of steelmaker Hoa Phat Group went up 1.5% and FPT of IT giant FPT Corporation closed 1.3% higher.
Five blue chips fell. BCM of Becamex Investment and Industrial Development dropped 2% and TPB of private TPBank closed 0.9% lower.
Foreign investors were net sellers to the tune of VND567 billion, mainly selling VPB of private lender VPBank and VNM of dairy giant Vinamilk.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.89% while the UPCoM-Index for the Unlisted Public Companies Market gained 0.10%.