Bear Stearns unable to meet a margin call, Goldman Sachs' Global Alpha fund just recovered their losses, Superfund just about to recover their previous losses, Tudor Jones shutting down a small-cap hedge fund, Ritchie Capital Management went broke. Why? During a easy to trade bull market?
Each situation was slightly different. Bear and Ritchie got hurt with illiquid markets. GS was leaning the wrong way in bonds and currencies. Tudor underperformed relative to certain benchmarks.