The index was mostly in the green in the morning but plunged by nearly 20 points in the afternoon before rising again to end with a near 9-point loss.
It still gained 0.57 percent, or 7 points this week, with three sessions in the red.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, rose 5.38 percent to VND21.76 trillion ($945 million). The bourse saw 81 stocks gain and 355 lose.
Tweny one out of 30 tickers in the VN30 basket was in the red, led by TCH of real estate company Hoang Huy Investment Financial Services, down 4.2 percent.
The ticker has ended in the red for five consecuitive sessions, plunging 13 percent.
TPB of private TPBank fell 3.8 percent to a near three-week low.
PLX of fuel distributor Petrolimex fell 2.9 percent, its biggest loss in a day since March 9, with news of a branch director in southern Long An Province arrested for suspected involvement in producing counterfeit fuel.
On the winning side, NVL of real estate developer Novaland Group surged 5.5 percent to a new historic peak, its 12th gaining session in a row.
Foreign investors were net sellers for the third session in a row to the tune of VND561 billion, with strongest pressure on VHM of real estate giant Vinhomes and HPG of steelmaker Hoa Phat Group.