Shares reversed May 13’s gains to tumble on both national stock exchanges on May 14.

Despite a few sessions of rallying due to reduced interest rates and the upcoming establishment of the nation's asset management company, investors may start to follow the "sell in May and go away" strategy.

According to HCM City Securities Co, the opening of the asset management firm might not occur as planned and could take until the third quarter.

"Meanwhile, the cash recently poured into the market was speculative money, which is unstable," said VietCapital Securities Co's Hanoi branch head of brokerage Pham Thanh Trung.

On the HCM City Stock Exchange, the VN-Index retreated over 1 percent to 483.85 points.

Losers overwhelmed gainers by 176-56.

While blue chips gave a boost to the HCM City market on May 13, they weighed on the VN-Index during the May 14 session.

Insurer Bao Viet (BVH), property developers Hoang Anh Gia Lai (HAG) and HCM City Infrastructure Investment, private equity group Masan (MSN), Phu Nhuan Jewelry (PNJ) and steelmaker Hoa Phat (HPG) lost over 1,000 VND per share, or between 1.8-6.1 percent.

Only Vietinbank (CTG) and software company FPT (FPT) posted modest gains of 0.5 and 1 percent.

The VN30, which represents the performance of 30 leading stocks in HCM City , also slipped 1.1 percent to 548.27 points.

Market value on the southern bourse reached only 77 percent of the previous day's level, or 772.3 billion VND (36.7 million USD), as 46.5 million shares changed hands.

On the Hanoi Stock Exchange, the HNX-Index shed 1.27 percent, reaching 59.89 points.

Nearly half of the listed stocks closed unchanged.

Trading value increased slightly compared to the May 13 session, standing at 240.5 billion VND (11.4 million USD).

Foreign investors turned to be net sellers in HCM City with a margin of 2.6 billion VND (123,800 USD), but they remained buyers in Hanoi by 7.68 billion VND (365,700 USD).-VNA