It's been over a year since I last posted on liar loans -- these are mortgages which the borrower obtains despite offering no documentation on their income, employment or assets. These liar loans were also known as Ninja loans -- which is short for no income, no job, and no assets. The Associated Press reports that such liar loans will add $100 billion to the losses our economy is already suffering thanks to $400 billion worth of losses from subprime mortgages.

The problem we face as an economy is that it's hard to see where the liar loans end and the collateralized debt obligations (CDOs) and other asset-backed securities begin. In a sense, they are all liar loans. In the case of the mortgages, borrowers created paperwork that was inconsistent with their actual financial condition so they could get the money. In the case of CDOs, the issuing investment bank bought a AAA rating from a rating agency which created the illusion that the security was safe. Conceptually, there is little difference -- both depended on essentially forged paperwork to make the loan go through.

Why did banks issue liar loans? They were afraid to lose market share. But that doesn't make it right. As my mother used to say to me, if the other kids jumped off the Empire State Building, would you do it too? AP brings this to life in an interview with David Zugheri, co-founder of Texas-based lender First Houston Mortgage who said, "Everybody drank the Kool-Aid. They knew if they didn't give the borrower the loan they wanted, the borrower could go down the street and get that loan somewhere else.''

How vulnerable is your mutual fund to the ongoing mortgage meltdown? In this series, BloggingStocks contributor Lita Epstein, author of more than 20 books including Trading for Dummies and The Complete Idiot's Guide to Improving Your Credit Score, digs into mutual funds' holdings looking for securities with exposure to the currently shaky credit markets.

The first inkling I got that Fidelity might be tied to the SIV bailout was a story last week in The Wall Street Journal that indicated Fidelity's Prime Money Market Portfolio owned $402 million medium-term notes in Gordian's Sigma Finance Inc. as of the end of August [subscription required]. Taking a closer look at Fidelity Funds, I found two broad market bond funds with significant exposure to the mortgage-backed and asset-backed credit categories now showing signs of trouble.

As of 9/30/2007 Fidelity Ultra Short Bond Fund holds 42.4% of its assets in asset-backed securities, 17.5% in collateralized mortgage obligations and 15.2% in commercial mortgage-backed securities. That's 75.1% of its assets in securities tied to the credit markets that are now showing signs of trouble. While I'm not saying that 75% of this fund's assets are in trouble, what I am asking is, do you really want that much exposure to these markets in this volatile time?

As of 9/30/2007 Fidelity Short-Term Bond Fund holds 23.1% of its assets in asset-backed securities, 13.5% in collateralized mortgage obligations, and 11.6% in commercial mortgage-backed securities. That's almost half of its assets in the most volatile parts of the credit markets. If you do hold these funds, you need to decide if you want this level of exposure to these risky credit markets right now.

In reviewing bond funds this morning, these two Fidelity bond funds were less-diversified than many of its peers. While their yields may be high, you must decide whether the risk is worth it.

Lita Epstein is the author of more than 20 books including the "Pocket Idiot's Guide to Investing in Mutual Funds."