The fourth-largest brokerage firm in South Korea collapsed on Friday , stocks plunged to an 11-year low and the nation's vaunted opening of its bond market to foreigners attracted only $700,000 in purchases, the latest signs of deterioration in the biggest victim of Asia's financial crisis.

''This is a Korean tragedy,'' said Park Young Chul, chief trader at Hyundai Securities. ''There is no sense of the bottom in the financial markets.''

Stocks did, however, stage something of a rebound today, with the benchmark index rising 2.6 percent in the short session of Saturday trading. Analysts said the gain reflected some new optimism that the country's political leaders would be cooperative with the international efforts to arrange a financial bailout for South Korea.

Friday's dismal tone was set early on when Kukdong Group, one of South Korea's conglomerates, said it had sought court receivership for its securities arm, Dongsuh Securities, the nation's No. 4 brokerage firm.