Enough about Goldman Sachs. J.P. Morgan is shaping up to be the real winner on Wall Street during this credit crisis.

The bank has so far emerged relatively unscathed from the subprime write-downs and loan losses that have plagued its Wall Street competitors. It wrote down just $1.3 billion in the fourth quarter of 2007, and its loan-loss provisions rose to $2.5 billion. That's just a tiny drop in the bucket of losses worth some $285 billion worldwide so far.

That news in January sent its shares up just enough to nudge J.P. Morgan's market cap above Citigroup's for the first time. It's currently second in size only to Bank of America.  

And now it's using its strong balance sheet and diverse revenue streams to influence other banks that haven't been so fortunate.

According to the Wall Street Journal, J.P. Morgan's vice chairman, James Lee, warned the Carlyle Group's David Rubenstein last week that the lenders (J.P. Morgan being one) behind its ailing Carlyle Capital unit would seize their assets unless it was bailed out.

And today, of course, it's J.P. Morgan that has come to the rescue of Bear Stearns, which is facing such a dire liquidity crisis that it was unable to last on its own until March 27, when the Federal Reserve would have been able to lend it funds.

Being a commercial bank, J.P. Morgan is able to borrow funds from the Federal Reserve's discount window and then re-lend them to Bear for 28 days. It issued a statement saying it does not believe the loan exposes it to any significant credit risk.

J.P. Morgan is also working with Bear "on securing permanent financing or other alternatives for the company."

It's not yet clear what J.P. Morgan gets out of the deal, but because this is Wall Street, it's certain that they didn't do it out of the kindness of their hearts.

According to the Associated Press, it was Bear Stearns and the Fed that approached J.P. Morgan about the financing. The two banks also discussed a potential deal, whereby J.P. Morgan would buy Bear Stearns outright, according to a person close to the talks.

Speculation that J.P. Morgan would make a major acquisition in 2008 has swirled for months, but most believed it would be in the commercial banking space, not investment banking.

But if J.P. Morgan's chief Jamie Dimon did entertain the thought of acquiring Bear Stearns during their urgent talks this week, he could come out looking smarter than ever to have engineered this loan first.

Bear Stearns is worth about 40 percent less today than it was yesterday.