The second graf of the Journal's story on Goldman's massively profitable second quarter:

With competitors such as Lehman Brothers Holdings Inc. and Bear Stearns Cos. gone, and others like Citigroup Inc. flailing, Goldman appears to be pulling off one of the biggest market-share grabs in Wall Street history.

In fairness, some of this market-share poaching came in areas like stock underwriting, which aren't what you think of as systemically risky activities. (Unlike, say, selling credit default swaps, in which ramping up your market share might not be the greatest idea. Just ask the folks at AIG Financial Products...) 

Also, somewhat remarkably, Goldman managed to vaccuum up its $3.4 billion profit by cutting its leverage almost in half:

At the same, Goldman reduced its leverage ratio, a measure of how much it is using borrowed money to magnify bets. That ratio fell to 14.2 at the end of the quarter, from 27.9 at the beginning of 2008.

That would obviously make the company less of a systemic risk. Still, there's no reason to think that leverage ratio is set in stone (unless Obama's regulatory reform efforts--or a the future systemic risk regulator--do the setting). And if Goldman returns to the old amount of leverage after getting a lot bigger, well, suffice it to say things could end badly. Particularly since Goldman made its money this quarter by taking on a lot more risk. Again, from the Journal:

By the end of the quarter, its VAR, or "value at risk," had risen by 33% from the year-ago level, to $245 million, up from $240 million in the previous quarter. VAR represents an estimate of how much the firm could lose in a single day.

Sounds like Barney Frank will have something to chew over during his hearings this summer.

Update: Speaking of market share and getting bigger than too big--it's worth pointing out that JP Morgan far outpaces Goldman in this regard, thanks in part to its absorption of Bear Sterns and Washington Mutual last year. 

--Noam Scheiber