Value investors are contrarian by nature. They want to buy when everyone else is cashing out, and sell when sentiment is driving asset prices ever higher. So when dyed-in-the-wool value investor and founder of Oaktree Capital Management Howard Marks spoke at the Morgan Stanley Financials Conference earlier today you might have expected him to warn people against being too optimistic, but you would only be half right. “Today’s markets call for caution, not aggressiveness, and my mantra for Oaktree for the last almost three years now has been move forward, but with caution,” said Howard Marks, Thomson Reuters reported. “I…