The index fluctuated in the 1,290 range throughout the day and closed 0.12 points lower.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 9 percent to VND23.43 trillion ($1.03 billion). The bourse saw 228 tickers lose and 145 gain.
The VN30 basket, comprising the 30 largest capped stocks, saw 22 tickers in the green compared to three Monday.
PDR of Phat Dat Real Estate Development led with a 4.6 percent gain, followed by VJC of budget airline Vietjet, up 2.1 percent, and SAB of brewer Sabeco, up 1.7 percent.
VJC is now at its highest since early May, while SAB is still on a downward trend that began mid-January.
MWG of electronics retail chain Mobile World rose 1.5 percent, while BVH of insurance company Bao Viet Holdings gained 1.2 percent.
Seafood processing was the top gaining sector with a 2.08 percent increase followed by mining, up 1.68 percent.
Six blue chip tickers ended in the red, with SSI of leading brokerage SSI Securities Corporation losing 3.5 percent from its peak, and VIC of biggest private conglomerate Vingroup falling 0.8 percent, its third losing session in a row.
Foreign investors ended a chain of 10 net selling sessions with a net purchase of VND132 billion, with strongest pressure on SSI and VHM of real estate giant Vinhomes.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 0.91 percent while the UPCoM-Index for the Unlisted Public Companies Market lost 0.36 percent.