Speaking of Madoff, I had a friend who was in one of the feeder funds. Getting 8%. I kept on telling him over 3 years that he should consider that a Junk Bond type investment. After 3 years I got him to cash in. It was about 20% of his portfolio. 9 months later, Madoff was caught. The guy with the feeder fund got trashed for 15 Mil or 75% of his portfolio.
Remember the 7 day floaters? Those gave about a 1 year warning sign before they went illiquid. Dodged that one too. If it is really good, stay for awhile, but always be ready to jump out. Greed short term is manageable but not "perma-greed"