The index went sideways throughout the day and closed one point higher. It has gained 36 points in the last five sessions.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 13 percent to VND21.95 trillion ($967 million).
Foreign investors net sold VND739 billion, highest since January 21, with focus on VIC of biggest private conglomerate Vingroup, HPG of steelmaker Hoa Phat Group and NVL of real estate developer Novaland Group.
The VN30 basket, comprising the 30 largest capped stocks, saw 11 tickers in the green, led by POW of electricity producer Petrovietnam Power Corporation with a 4.2 percent gain to the highest in nearly a month.
SAB of brewer Sabeco also hit a one-month high with a 2.1 percent increase.
MSN of conglomerate Masan Group rose 2 percent after the company announced it had acquired a 51 percent stake in Phuc Long tea chain.
Other gainers included PLX of fuel distributor Petrolimex, up 1.9 percent, and GAS of state-owned Petrovietnam Gas, up 1.8 percent.
Sixteen blue chip tickers fell, with VIC of biggest private conglomerate Vingroup falling 2 percent to the lowest in over a year.
The ticker has closed in the red in four straight sessions and has lost nearly 12 percent this year.
VHM of real estate giant Vinhomes closed 1.7 percent lower, and VJC of budget airline Vietjet fell 1.5 percent.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.95 percent while the UPCoM-Index for the Unlisted Public Companies Market gained 0.57 percent.