The boss of a successful US hedge fund has quit the industry with an extraordinary farewell letter dismissing his rivals as over-privileged "idiots" and thanking "stupid" traders for making him rich.

Andrew Lahde's $80m Los Angeles-based firm Lahde Capital Management made a huge return last year by betting against subprime mortgages.

Yesterday the 37-year-old told his clients that he had hated the business and had only been in it for the money. And after declaring he would no longer manage money for other people, because he had enough of his own, Lahde said that instead he intended to repair his stress-damaged health; he made it clear he would not miss the financial world.

"The low-hanging fruit, ie idiots whose parents paid for prep school, Yale and then the Harvard MBA, was there for the taking," he wrote. "These people who were (often) truly not worthy of the education they received (or supposedly received) rose to the top of companies such as AIG, Bear Stearns and Lehman Brothers and all levels of our government," he said.

"All of this behaviour supporting the aristocracy only ended up making it easier for me to find people stupid enough to take the other side of my trades. God bless America."

Lahde became one of the biggest names in the investment industry when one of his funds produced a return of 866% last year, largely by forecasting the US home loans industry would collapse.

In his farewell letter, which concluded with an appeal for the legalisation of marijuana, Lahde said he was happy with his rewards and did not envy those who had made even more money.

"I will let others try to amass nine, 10 or 11 figure net worths. Meanwhile, their lives suck," he wrote, citing a life of back-to-back business appointments relieved only by a two-week annual holiday in which financiers are still "glued to their Blackberries".

Lahde's retirement came amid an implosion among the hedge fund industry - some 350 of the funds have liquidated this year, according to Hedge Fund Research.

His final words of advice? "Throw the Blackberry away and enjoy life."