John Mauldin says high unemployment and coming big tax hikes are creating a “50/50” chance the U.S. will dip back into recession in 2011. Mauldin tells Bloomberg that means a 40% plunge could hit the stock market, and that investors should treat the current market as a trader’s market.

[youtube=http://www.youtube.com/watch?v=Bc2bqMgzlO4]