The New York Times [registration required] reports that the subprime meltdown has zipped across the Pacific to wipe out the fortunes of Japanese housewives who trade currencies after putting their children to sleep. Betting an average of $9.1 billion a day -- 20% of daily foreign exchange (FX) volume -- on a decline in the Yen relative to the dollar, many of these housewives were wiped out when the August credit crunch caused U.S. hedge funds to panic -- driving up the Yen's value and tanking their trades.

Japanese online investors lost $2.5 billion trading currency in August. And for many Japanese households, housewives' FX trading had been kept in the closet. Japanese tradition frowns on making money through means other than hard labor -- such as market speculation.

But this taboo is out in the open thanks to Mayumi Torii, according to the Times, a 41-year-old mother of one who said she earned $150,000 since she started margin trading in currencies early in 2006. Torii now appears on TV promoting her FX Beauties Club so she can "stand on my own economically," a necessity she discovered after her first marriage ended in divorce, and she and her son had to live off her meager savings. "I never want to feel that vulnerable again," she said.

Despite their losses, many of these housewives plan to renew their FX trading -- they claim there is no other way to make money so quickly.

I had never known about this corner of the FX market before and would never have guessed that the subprime mortgage meltdown would damage it. These weekly subprime meltdown eruptions are offering me a great opportunity to learn more about our global financial markets. Unfortunately, that education is costing investors real money.

Peter Cohan is president of Peter S. Cohan & Associates, a management consulting and venture capital firm. He also teaches management at Babson College and edits The Cohan Letter.