The index closed 33.7 points lower in its fourth losing session, after plunging 38.6 points Friday.
Trading on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, dropped 17.9% to VND12.02 trillion.
The VN30 basket, comprising the 30 largest capped stocks, saw 27 blue chips sinking.
Ten of them hit floor prices, including GVR of Vietnam Rubber Group, MWG of electronics retail chain Mobile World and PLX of fuel distributor Petrolimex with a 7% decline.
Other major losers were TCB of the largest private lender Techcombank, VHM of property giant Vinhomes and BID of state-owned lender BIDV.
TPB of private TPBank was the only gaining blue chip with a 0.2% rise.
Foreign investors were net buyers to the tune of VND71.5 billion, mainly buying FRT of FPT Digital Retail and MSN of conglomerate Masan Group.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, dropped 3.64% while the UPCoM-Index for the Unlisted Public Companies Market fell 2.7%.