Papa John's International Inc. PZZA, -3.34% shares surged in the extended session Monday following a report that hedge fund Trian Fund Management was exploring a takeover bid. Papa John's shares surged 19% after hours, following a gain of 0.1% to close at $50.42 Monday. Trian recently contacted the pizza chain for information as it considers a bid, according to The Wall Street Journal, citing unnamed sources close to the matter. In September, company founder John Schnatter, who owns about 30% of shares, was reportedly contacting private-equity firms to buy back the company.