Acacia Research Corp ., which buys and licenses patents, said Friday it completed a $157.5 million public offering of common stock . The company offered 5 million shares at $31.50 apiece, which was a 6 percent discount to Thursday's closing price of $33.53. The company granted underwriter Barclays Capital a 30-day option to buy up to an additional 750,000 shares to cover over-allotments. Acacia has about 37 million shares of common stock outstanding. Acacia's shares fell $1.31, or 3.9 percent, to $32.22 by midday Friday.