The VN-Index rose 0.31 percent on May 30 to close at 412.10 points, extending the rally to three sessions in a row as heavyweight stocks climbed.

Four blue chips hit ceiling prices, including insurer Bao Viet Holdings (BVH), food producer Masan Group (MSN), property and resort developers Vincom (VIC) and Vinpearlland (VPL), pushing the index up despite decliners outnumbering advancers by 168-68.

Around 63 per cent of decliners fell by almost 5 percent – the most they can sink in a single session – including many large caps like Phu My Fertiliser (DPM), software producer FPT (FPT), steel producer Hoa Phat Group (HPG), Vietcombank (VCB), Sacombank (STB) and PetroVietnam Finance (PVF).

Analysts of Vietnam International Securities Co ( VIS ) said "the market rebound was still haunted by the pressure of selling shares pledged as collateral in securities companies".

According to the preliminary statistics of VIS, total debts of 45 big brokerage houses (including short-term and long-term loans) were estimated at 47.5 trillion VND (2.3 billion USD), of which financing investors made up 33 trillion VND (1.6 billion USD).

If the market kept declining, securities firms would continue to face great pressure on short-term debts and they would likely be forced to sell mortgaged stocks to recover debts, VIS analysts said in a note.

On the HCM Stock Exchange, trading volume remained sluggish with over 27 million shares, worth around 515.8 billion VND (25 million USD), changing hands.

Refrigeration Electrical Engineering (REE) was the most active share on the bourse with over 3 million shares traded, posting an increase of 1.9 percent to close at 10,700 VND (0.52 USD).

On the Hanoi Stock Exchange, the HNX-Index lost a landmark of 70 points, declining 1.72 percent to 69.61, ending the two-day rally last week.

Trading volume decreased by 10 percent from the previous session on May 27 to 28.5 million shares, worth 301.7 billion VND (14.6 million USD), with losers nearly doubling gainers.

PetroVietnam Construction Co (PVX) was the most heavily traded share with 3.11 million shares exchanged, closing with an increase of 2 percent at 9,900 VND (0.48 USD). /.