The Justice Department launched its probe of Goldman Sachs (GS) before the SEC filed its civil fraud charge, and the probe casts a far wider net than the SEC did, Zachary A. Goldfarb and Jerry Markon of the Washington Post report.

This presumably contributed to Goldman's stock losing about $8 billion of market value yesterday.

Now, a probe is not the same as a charge: The Justice Department investigates lots of behavior and later concludes that criminal charges aren't warranted (and as citizens, we should be deeply thankful for that).

Given the outrage around Goldman, moreover, as well as the ongoing desire to find criminal behavior that contributed to the financial crisis, it would be surprising if the Justice Department were NOT investigating Goldman Sachs. Any prosecutor who found a smoking gun that hung a few Goldman executives would be lionized.

So it's not surprising that the Justice Department is looking at Goldman, and the investigation won't necessarily lead to charges.

But let's be clear about what's at stake.

If the Justice Department were to file criminal charges against Goldman Sachs (the firm, not just some executives), Goldman would likely go bust. It is highly unlikely that a financial firm could survive criminal charges. If prosecutors confined the charges to executives and didn't charge the firm itself, which is the more likely result, the firm would survive, but the headlines would stay nasty for years.

If the Justice Department has cast a wider net than the SEC investigation, moreover, there's a chance that the Justice Department will uncover something that the SEC didn't. And that's where the real risk lies.

Also, Goldman can't make a criminal investigation go away by just settling and writing a massive check, the way it can with the SEC case. Instead, the firm and its shareholders and employees will just have to wait and sweat.

If the Justice Department only recently opened its investigation, it could take months or even years.