VN-Index stayed in the red most of the day and closed nearly 11 points lower after rising nearly 42 points in the last two sessions.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, dropped 28 percent to VND16.77 trillion ($740.56 million), lowest since September 30 last year.
The VN30 basket, comprising the 30 largest capped stocks, saw 17 tickers in the red, with VCB of state-owned lender Vietcombank falling 3.7 percent after reaching a new peak Wednesday.
MSN of conglomerate Masan Group lost 3.4 percent, continuing its downward trend.
HPG of steelmaker Hoa Phat Group fell 3 percent, and CTG of state-owned lender VietinBank dropped 2 percent.
Most banking stocks closed in the red, with ACB of Asia Commercial Bank falling 1.6 percent and VPB of private lender VPBank losing 1.3 percent.
Ten blue chip tickers bucked the trend, with VNM of dairy giant Vinamilk rising 4.3 percent in its second gaining session.
VNM has been falling since January last year and on Tuesday hit the lowest since July 2020.
SAB of brewer Sabeco rose 3.5 percent, and TPB of private TPBank gained 2.6 percent.
Foreign investors were net buyers for the third straight session to the tune of VND135 billion with focus on LPB of Lien Viet Post Bank and TPB.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 0.13 percent while the UPCoM-Index for the Unlisted Public Companies Market lost 0.29 percent.