Short squeezes, sure. But they're not pessimists. More like cynics. In fact, today's most famous short seller, Jim Chanos, runs a firm called "Kynikos" (Greek for "cynic").
Apart from short squeezes, markets generally grind higher and crash lower. The left tail of the distribution is usually the thicker, meatier, juicier one. But the mode is usually slightly positive. So it's not usually the blood of cynics, but rather the patience of optimists and the persistence of hard workers, that brings markets higher.
Apart from short squeezes, markets generally grind higher and crash lower. The left tail of the distribution is usually the thicker, meatier, juicier one. But the mode is usually slightly positive. So it's not usually the blood of cynics, but rather the patience of optimists and the persistence of hard workers, that brings markets higher.