Opening on 1,163.10, the VN-Index commenced freefall from 10:42 a.m., when national coronavirus contact tracing app Bluezone announced Hai Phong and Ho Chi Minh City were quarantining certain locations related to the country’s two new Covid-19 cases, with the warning "risk of 4th Covid-19 wave."

Within the next hour, panic selling, along with momentary trade freezes, caused the index to drop 25 points compared to its morning opening, with over 400 tickers on the Ho Chi Minh Stock Exchange (HoSE) in the red compared to just 58 in the green.

However, sentiment seem to have settled and buying pressure reappeared within the final 15 minutes of the morning session. Investors mostly bought up banking and securities blue chips, along with tickers in sectors like steel and manufacturing.

Buying pressure persisted in the afternoon, allowing the VN-Index to pull back most of morning losses.

By the session’s end, the HoSE had remained predominantly in the red, with 339 stocks losing and 122 gaining. Total trading volume was VND15.61 trillion ($675.18 million), down 1 percent over the previous session.

Blue chips outperformed the general market, with the VN30-Index for the stock market’s 30 largest caps adding 0.22 percent, albeit with 11 tickers gaining against 19 that lost.

Topping gains was HPG of steelmaker Hoa Phat Group, up 2.7 percent. It was followed by VJC of budget carrier Vietjet Air, up 1.9 percent, and VIC of private conglomerate Vingroup with 1.8 percent.

Other major gainers included REE of appliances maker Refrigeration Electrical Engineering and STB of private Sacombank, both up 1.1 percent, MWG of electronics retailer Mobile World, up 0.9 percent, and POW of electricity generator PetroVietnam Power, with 0.8 percent.

The real estate sector were the worst performers in the basket of blue chips. KDH of Khang Dien House topped losses with 2.9 percent, followed by PDR of Phat Dat Real Estate, down 1.1 percent, VHM of Vinhomes, 1 percent, TCH of Hoang Huy Group, 0.9 percent, and NVL of Novaland, with 0.6 percent.

Other major losers included VRE of mall operator Vincom Retail, which shed 2 percent, BVH of insurance giant Bao Viet Group, 1.7 percent, GAS or energy giant PetroVietnam Gas, 1.2 percent, and VNM of dairy firm Vinamilk, with 1.1 percent.

Meanwhile, the HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, added 1.41 percent, while the UPCoM-Index for the Unlisted Public Companies Market dropped 0.65 percent.

Vietnam’s three biggest state-owned lenders by assets, CTG of VietinBank, BID of BIDV and VCB of Vietcombank all slumped, by 0.9 percent, 0.4 percent and 0.2 percent respectively.

Foreign investors returned as net sellers, to the tune of VND290 billion on all three bourses. The most net sold stocks were CTG of VietinBank, down 0.9 percent, VIC of Vingroup, and MBB of mid-sized state-owned Military Bank, down 0.2 percent.