How do companies with such great assets go belly up within days once a cascade of bad things start happening? At the outset of 2008 we had five major independent investment banks and now we have two (Goldman Sachs & Morgan Stanley). A core reason is that the leveraged finance business model is a very poor one. It allows you to make a killing when times are good, but on the flip side it can bankrupt you within days when the tide turns. That is not a risk-reward scenario that companies should embrace.

Imagine how easy it is to get caught up in the leverage game. Pretend you have $10 and are allowed to borrow $300 against it, for a leverage ratio of 30-to-1 (a common ratio for investment banks in recent years). If you are paying 5% interest on the loan and can earn just 6% on the $310 in capital you now control, you can earn a profit of $3.60 ($18.60 less $15.00 in interest) on your original $10.00 in capital for a return of 36%. Pretty cool, huh?

Well, only when you actually make money on what you are investing the money in. Consider the same example when your investment loses 5% of its value. After paying interest on the loan, you only have $279.50 left but still owe $300 to the lender. Now you are in trouble. To pay back the loan you need to borrow another $21.50 (if someone will lend it to you) and even if you can do that, you have lost your original $10 in capital.

The leveraged finance game, at least at the level these investment banks were playing it (leverage ratios of 25, 30, or 40 to 1) is very, very dangerous. Investors beware.

A final note about business models. AIG (AIG) is trying to sell assets in order to raise at least $40 billion in new capital because the ratings agencies may downgrade their credit rating if AIG can't come up with the new money. Reports are that a ratings change could bankrupt AIG within days if that downgrade should occur.

What kind of business model is this? Moody's and S&P downgrading your credit rating results in your company going bankrupt in 2-3 days? Not only is that simply ridiculous in terms of relying on one party to remain solvent, but even more unreal is that these are the same ratings agencies that don't have a clue how to rate anything. Remember, they had triple A ratings (the highest possible) on packages of subprime mortgages! If subprime mortgages are of the highest credit quality, what would prime mortgages be considered?

Short term, the unraveling of these firms will hurt, but long term, from what we are learning about these business models, maybe they should never have been anywhere near as big as they were to begin with.

Full Disclosure: No position in AIG at the time of writing