JPMorgan Chase (NYSE:JPM) reported fourth-quarter earnings this morning, the first big bank to do so. Overall, they were fantastic -- a $3.3 billion, or $0.74-per-share, profit on revenue of $25.2 billion. For full-year 2009, net income was $11.7 billion, or $2.26 per share. Not bad for one of the deepest recessions in decades.

But before declaring victory, I always like to dig into the earnings supplemental and find out exactly where the income came from. When broken out by segment, here's how it looked last quarter:

Segment

Q4 Net Income

Investment banking

$1.9 billion

Retail financial services

($399 million)

Card services

($306 million)

Commercial banking

$224 million

Treasury and securities services

$237 million

Asset management

$424 million

Corporate/private equity

$1.2 billion

Total

$3.3 billion

Ah … just like every quarter of the past year, the money's flowing heavily in investment banking and corporate (essentially trading), while traditional commercial banking segments are still a mess.

To show where exactly the investment banking segment is pulling it in, we can dissect that segment further. Since JPMorgan doesn’t break out the net income, here is a breakdown of the $4.9 billion revenue that led to the $1.9 billion in investment banking net income:

Segment

Q4 Revenue

Advisory

$611 million

Equity underwriting

$549 million

Debt underwriting

$732 million

Fixed-income markets

$2.7 billion

Equity markets

$971 million

Credit portfolio

($669 million)

Total

$4.9 billion

Note how incredibly important the fixed-income markets line is.

Look at it this way: Investment banking accounts for 58% of net total income, and fixed-income accounts for 55% of investment banking revenue. Fixed-income revenue was down by almost half compared with the previous three quarters, but it's still a huge contributor to the bottom line.

Digging deeper into the credit quality of commercial banking, here's what you'll find:

Segment

Q4 2009

Q3 2009

Net charge-off rate

1.92%

1.11%

Allowance for losses/average loans

3.03%

2.95%

Nonperforming loans/average loans

2.80%

2.21%

And for credit cards …

Segment

Q4 2009

Q3 2009

30-days+ delinquent

6.28%

5.99%

90-days+ delinquent

3.59%

2.76%

Net charged-off rate

9.33%

10.30%

Bottom line
These results are good, but need an important caveat: Capital markets are extremely strong, while traditional lending remains quite bad. This is exactly why Goldman Sachs (NYSE:GS) has done extremely well, JPMorgan has done pretty well, and Citigroup (NYSE:C) and Bank of America (NYSE:BAC) have done not so well over the past year. Banking results have tended to track the segmental mix of a company's balance sheet more than they have the skill and expertise of that bank.