You know what they say, ‘one man’s loss is another man’s gain’, well that certainly is true with regard to the subprime mortgage meltdown. Canny trader’s working for Goldman Sachs bet against lenders and won to the tune of $4 billion.

House prices are crumbling on both sides of the Atlantic, growing numbers of homeowners face repossession, financial markets are yo-yoing and the UK saw its first run on a bank in living memory. But for three audacious New York traders it all added up to a $4bn (£2bn) profit opportunity and the biggest jackpot in the history of Wall Street.

The young guns at the investment bank Goldman Sachs – none of them over 40 years old – were unmasked yesterday, prompting a wave of adulation and envy among their colleagues, and another bout of handwringing about Wall Street’s ability to make multibillion-dollar profits even as millions of ordinary people face losing their homes.

Dan Sparks and two underlings, Josh Birnbaum and Michael “Swenny” Swenson, placed what were in effect giant bets against the US mortgage market at the start of the year and watched their winnings tick higher and higher as the rising numbers of mortgage defaults spiralled into a worldwide financial crisis. Throughout the year, they battled with more cautious bosses who feared the bets were too big and too dangerous, but in part because of their success Goldman Sachs will post record profits next week. In doing so, the firm will stand alone on Wall Street, where rivals have suffered huge losses from the credit market meltdown.

The trio themselves are in line for bonuses of about $10m apiece from a record bonus pool at Goldman of about $19bn. “They are very embarrassed that their names have come out,” said a company source. “Until now, nobody had heard of them, including most of the people on the floor where they work.”

Hailed as canny heroes these three will reap enormous profits off the very backs of individual homeowners lured into low interest loans on over appraised properties. Their loss is Goldman Sachs gain. Also from the Wall Street Journal

Goldman’s success at wringing profits out of the subprime fiasco, however, raises questions about how the firm balances its responsibilities to its shareholders and to its clients. Goldman’s mortgage department underwrote collateralized debt obligations, or CDOs, complex securities created from pools of subprime mortgages and other debt. When those securities plunged in value this year, Goldman’s customers suffered major losses, as did units within Goldman itself, thanks to their CDO holdings. The question now being raised: Why did Goldman continue to peddle CDOs to customers early this year while its own traders were betting that CDO values would fall? A spokesman for Goldman Sachs declined to comment on the issue.

The structured-products trading group that executed the winning trades isn’t involved in selling CDOs minted by Goldman, a task handled by others. Its principal job is to “make a market” for Goldman clients trading various financial instruments tied to mortgage-backed securities. That is, the group handles clients’ buy and sell orders, often stepping in on the other side of trades if no other buyer or seller is available.

The group also has another mission: If it spots opportunity, it can trade Goldman’s own capital to make a profit. And when it does, it doesn’t necessarily have to share such information with clients, who may be making opposite bets. This year, Goldman’s traders did a brisk business handling trades for clients who were bullish on the subprime-mortgage-securities market. At the same time, they used Goldman’s money to bet that that market would fall.

I don’t pretend to understand the nuanced world of high finance but I can say that all this feels intuitively wrong and gives full argument towards achieving local sustainability.