Never any surprises with Goldman Sachs (NYSE:GS). No matter what gets thrown its way, it finds a way to generate ridiculously huge numbers.

Even if they aren't, oh ... what's the word ... true?                  

OK, Goldman's fourth-quarter $4.95 billion, $8.20 per share profit that blew expectations away was legitimate. No rules were broken, as far as I know. But digging deeper shows just how important it is to take these headline numbers with a grain of salt.

Breaking out major segments' revenue for the quarter, here's what you get:

Segment

Q4 2009

Q3 2009

Investment Banking

$1.6 billion

$899 million

Trading/Principal Investments

$6.4 billion

$10 billion

Asset Management

$1.6 billion

$1.4 billion

Total Net Revenue

$9.6 billion

$12.4 billion

That looks pretty bad. Revenue tumbled, primarily in the trading segment. JPMorgan Chase (NYSE:JPM) and Citigroup (NYSE:C) showed the same trend when they reported earnings. Same with Bank of America's (NYSE:BAC) results yesterday, when I wrote, "Goldman reports earnings tomorrow morning. If the same trend in capital markets continues, it could be a very, very interesting report."

And it is. The two largest divisions of trading and principal investments fell dramatically:

Segment

Q4 2009 Revenue

Q3 2009 Revenue

Fixed Income, Currency, Commodities

$4.0 billion

$6.0 billion

Equities Trading

$1.0 billion

$1.8 billion

But if revenue fell so much, why was net income so strong?

You've probably heard by now; every news agency picked up on it: Goldman reduced its compensation expense last quarter, leaving more money for shareholders.

What hasn't been discussed enough is the extent of which this took place:

Compensation and Benefits Expense

Q4 2009

Q3 2009

Q2 2009

Q1 2009

($519 million)

5.4 billion

6.6 billion

4.2 billion

You're seeing that right: Goldman computed a negative compensation expense for the quarter. That's the equivalent of paying its employees nothing. Now, of course, workers will still get paid for the year, since year-end bonuses accrued heavily over the previous three quarters.

But this "payless" quarter is obviously a one-time deal. If you take a normalized compensation expense -- heck, take half a normalized compensation expense -- it's safe to say net income would have been reduced by $2-$3 billion. When we're talking about a $4.95 billion profit, that's sort of ... kind of ... completely ... important.

What do you think? Share your thoughts in the comment section below.