
Finance has gotten so complex, with so much interdependency. I argued with Alan Greenspan some about this at [Washington Post chairman] Don Graham's dinner. He would say that you've spread risk throughout the world by all these instruments, and now you didn't have it all concentrated in your banks. But what you've done is you've interconnected the solvency of institutions to a degree that probably nobody anticipated. And it's very hard to evaluate. If Bear Stearns had not had a derivatives book, my guess is the Fed wouldn't have had to do what it did.
I read a few prospectuses for residential-mortgage-backed securities - mortgages, thousands of mortgages backing them, and then those all tranched into maybe 30 slices. You create a CDO by taking one of the lower tranches of that one and 50 others like it. Now if you're going to understand that CDO, you've got 50-times-300 pages to read, it's 15,000. If you take one of the lower tranches of the CDO and take 50 of those and create a CDO squared, you're now up to 750,000 pages to read to understand one security. I mean, it can't be done. When you start buying tranches of other instruments, nobody knows what the hell they're doing. It's ridiculous. And of course, you took a lower tranche of a mortgage-backed security and did 100 of those and thought you were diversifying risk. Hell, they're all subject to the same thing. I mean, it may be a little different whether they're in California or Nebraska, but the idea that this is uncorrelated risk and therefore you can take the CDO and call the top 50% of it super-senior - it isn't super-senior or anything. It's a bunch of juniors all put together. And the juniors all correlate.
Este es el link del artículo completo que vale la pena leer.
http://money.cnn.com/2008/04/11/news/newsmakers/varchaver_buffett.fortune/index.htm
Espero pegar después la carta que cada año Warren Buffett le escribe a los accionistas de su vehículo de inversión Berkshire Hathaway.





























