SAN FRANCISCO (MarketWatch) -- David Einhorn generated gains of almost 4% in October, according to the investment results of Greenlight Capital Re, a reinsurer that invests its premiums with the hedge fund manager.

Rating agencies used to be business that value investors loved to own, but that seems to be changing.

Shares of Moody's (MCO) are down $2.18 to $25.97 in the wake of bearish comments from Greenlight Capital (GLRE) manager David Einhorn. He said he's shorting the credit-ratings company calling the brand “tarnished.” Option volume is running 7x the daily average with 16 000 puts compared to 2 400 calls. The focus is the June $26 put which has traded over 4 000 contracts against prior open interest of just 420 contracts. There's also buying in July $25 and $24 puts whose volume has exceeded prior open interest. Implied volatility has jumped to 65% from 49% a day earlier.Shares of F5 ...

David Einhorn -- head of Greenlight Capital (GLRE) perhaps best known for calling "baloney" on Lehman Brothers' financial statements last year -- recently said he's shorting Moody's (MCO). He argues that the investing community doesn't believe in its ratings and that those who receive the best ratings end up abusing them by borrowing excessively. He's absolutely right of course. In this space I've been writing for months now about the flaws of the rating agencies. I'm short both Moody's and McGraw-Hill (MHP) parent of Standard and Poor's. McGraw-Hill is nominally a cheaper stock than Moody's but its other business -- traditional publishing -- is ...

David Einhorn generated gains of almost 5% during the first quarter, recovering from a difficult year in 2008, according to the investment results of Greenlight Capital Re, a reinsurer that invests its premiums with the hedge fund manager.