The index started off with a more than six-point rise before plunging into the red, with many investors saying they were unable to place or modify orders while stock trading boards at some brokerages malfunctioned.

It then climbed back up to close with a near 8-point increase. The index has closed in the green during eight of the last nine sessions, gaining over 75 points.

The index rose 7.15 percent in May, surpassing the 1,300 level for the first time on May 25 and has secured several new peaks since.

The VN30 basket, comprising the 30 largest capped stocks, saw 14 tickers in the green led by HPG of steelmaker Hoa Phat Group with a ceiling increase of 6.8 percent.

Trading volume of HPG rose 235 percent from the average of the last 10 previous sessions. HPG’s price now stands at VND52,700 ($2.29), having risen 73 percent since the beginning of the year.

SSI of leading brokerage SSI Securities Corporation rose 6.2 percent to a new peak. It has surged 36 percent in May.

STB of Ho Chi Minh City-based lender Sacombank rose 6.1 percent, its sixth session in the green.

Other strong gainers were CTG of state-owned lender VietinBank and TPB of private TPBank, both up 3.7 percent, and BID of state-owned lender BIDV, up 3.3 percent.

On the losing side VRE of retail real estate arm Vincom Retail fell 3.8 percent, followed by MWG of electronics retail chain Mobile World, down 2.9 percent.

Foreign investors turned net sellers this session to the tune of VND1.68 trillion, with strongest pressure on HPG, MBB of Military Bank and VCB of state-owned lender Vietcombank.

The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, gained 2.38 percent while the UPCoM-Index for the Unlisted Public Companies Market rose 3.09 percent.