Samuel Koh, Asian head of domestic derivatives trading at HSBC in Hong Kong, has left the firm. Koh joined from Citigroup in 2001 to spearhead its drive into local currency derivatives trading throughout the regional markets (DW, 3/5/01). Koh declined all comment. He reported to Anita Fung, treasurer and Asia-Pacific head of global markets in Hong Kong. Fung did not respond to messages.