Vietnam's stock market lost nearly 2 per cent Tuesday to fall to levels last seen in February 2006.
The VN-Index closed down 6.48 points, or 1.97 percent, at 322 points, reported dpa.
"I am very sad to see Vietnam's market has dived so deep," said analyst Vo Quoc Khanh of FPT Securities.
"I am panicking ," said Nguyen Thanh Hai, a trader at Bao Viet Securities. "I can't sell my stock."
Market volume rose to 15.4 million shares valued at 23 million dollars, up from Monday's 11.9 million shares valued at 3.9 million dollars.
Khanh said market trends would continue to be negative.
"It is very difficult to be optimistic about the stock market in the next few trading days," said Khanh. "Vietnam's macroeconomy still has a lot of uncertainties, and the global financial market crisis is causing more problems."
Vietnam has only recently begun to tame an inflation rate that topped 30 per cent earlier this year. The country's trade deficit for 2008 could hit 20 billion dollars, nearly a quarter of its GDP, and businesses are having trouble accessing credit due to double-digit interest rates.
Hai said foreign investors were dumping shares across the board since the beginning of October, and noted that the market was worse than he could have imagined two months ago.
Local media Tuesday quoted officials at Vietnam's State Securities Commission saying they will intervene to halt trading if the market continued to fall sharply.
"The SSC will not let the market fall freely," Nguyen Son, head of the commission's market development department, told the newspaper Nguoi Lao Dong. "We will take urgent measures to help boost the market, which has lost 65 per cent so far this year."
Son did not elaborate what measures it would take.
Vietnam's stock market has fallen 141 points, or 30 per cent, since the start of October.