Goldman’s stock traders lost $112 million of the firm’s own money in the second quarter. It’s not even in the same tank, or really ocean, as JPMorgan’s $5.8 billion loss, but it was a huge drop from the nearly $900 million in profit the bank made from trading stocks in the first quarter. And Goldman said that loss includes gains it made in its private equity business, which means its losses from its public stock holdings could have been considerably larger than just $100 million.

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Goldman’s bond traders did better, but not much. Profits from debt trading fell 62% in the quarter to $222 million. In all, revenue from Goldman’s own trading operations plunged 90% to $169 million in the quarter from three months ago.

Goldman has long been known as a trading house, and has generally done a better job than rivals at producing consistent profits investing the firm’s own money. The bank had a string of quarters in 2009 and 2010 in which it went without a single down trading day.

That was clearly not the case this quarter, but it’s not clear what caused the firm problems, and a Goldman spokesman declined to comment on the firm’s specific investments. In the past few months, Goldman has said that it’s looking to beef up its business in Europe, which has been hit by debt concerns and an economic slowdown. But Goldman said it took a cautious stance on Europe in the quarter.

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Another possible explanation could be Facebook (FB). Goldman raised $235 million selling a portion of its investment in Facebook during the quarter. That was nearly double what Goldman paid for those shares just over a year ago. But Goldman, like other banks, has to constantly reprice on their books the value of its investments whether it sells them or not. In the year leading up to Facebook’s IPO, the private value of the shares rose. Some private transactions seemed to suggest that Facebook’s shares were worth more than the $38 the company eventually sold its stock at in its May IPO. Since then, Facebook’s shares have fallen to a recent $27.50. That could be lower than where Goldman marked its investment at the end of the first quarter, producing a loss.

Goldman has said it has shrunk its trading business in preparation for Dodd-Frank’s Volcker rule and other regulatory reforms that will make it harder for banks to make risky bets. But the Volcker rule hasn’t been put into place yet. And it’s not clear what changed from a quarter ago, when so-called principal transactions, which is when the bank risks its own money rather than completing a trade for a customer, was a big money maker. Goldman’s value-at-risk, which tracks how much the firm could lose in one day and generally is seen as a measure of how much trading the firm is doing, was $92 million in the quarter, basically unchanged from the quarter before.

Some have guessed that Goldman has shifted a portion of its risky trading into its market making unit, a business that is allowed under the Volcker rule. But that unit saw a drop in revenue in the second quarter as well, down 46% from the first three months of the year.

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Goldman has lost a lot of its top traders to hedge funds and elsewhere since the financial crisis, and that could be finally catching up with the firm. Overall, Goldman’s earnings were better than analyst expected. But that’s only because in the past month, analysts had cut their estimates for what Goldman could earn more than any of the firm’s rivals. What’s clear, is that at least for now, Goldman no longer appears to be the profit powerhouse it once was.

The good news is that the firm may be starting to realize that. Chief financial officer David Viniar told analysts that he expects the firm will cut $500 million in expenses by the end of the year, mostly by laying off a number of the firm’s higher paid employees. Still, when asked by an analyst when Goldman plans to bring its high compensation in line with other Wall Street firms, Viniar demurred, basically saying that Goldman employees were worth more. Self-realization for masters of the universe is a slow process.