NEW YORK—Stock analysts on Wall Street fled in terror after being spooked by the rare but deadly boar market that reared its head at closing bell Monday. "I have no idea what to expect," stock analyst Christopher Mattson said. "This market is highly unpredictable—tusked and savage and covered with coarse, bristly hair. I didn't know if I should buy, sell, or shoot." Mattson said he hopes stocks will soon perform again like they did two weeks ago, when brokers were soothed by the graceful movements of a swan market.