Shares of AmSurg are up more than 2 percent in mid-day trading and earlier reached $31 for the first time, pushing the company's market cap ever so close to $1 billion. The surgery center operator has now climbed almost 20 percent so far this year — even though it's been very quiet on the corporate news front — and has outpaced the S&P 500 by 12 percent in the past 12 months.