Pioneer is acquiring about 28,000 net acres in the Midland Basin in Texas for $435 million. It also said it plans to add five rigs in the second half of 2016.
Pioneer priced the underwritten public offering of 5.25 million shares of its common stock for about $827 million and expects the deal to close by June 21.
Pioneer's stock fell more than 6 percent Thursday while Devon shares were slightly lower on the day.
Shares of Pioneer are up more than 21 percent this year, while Devon shares are up 8 percent.