Barry Ritholtz says that too many investors are underinvested in stocks, saying that the market rally has been “hated” by many. Ritholtz tells Bloomberg that pullbacks are a part of bull markets, but investors seem to take every minor pullback as a sign off disaster these days. He talks about how difficult it is to jump back into the market at the right time after you’ve jumped out. And he talks about how a myriad of factors drive the market — not just one, as the headlines often make it seem.