That thing inflating before us like the Ghostbusters Stay Puft Marshmallow Man? Now, we know it’s not a bubble. Nearly half of professional investors surveyed in Barron’s latest Big Money poll, published Thursday, said they were optimistic about the market’s potential over the next 12 months. It’s a major reversal from the pervasive pessimism that took hold earlier this year, and historically speaking, it looks pretty accurate, based on the length of past bull markets. SUBSCRIBE:  Receive more of our free ...