Shares of Calpine Corporation (NYSE:

) are lower on the session by 0.13%, trading at $15.70. Overall put volume is now running at 2.10x the daily average, with 56% of all puts traded being purchases on the offer. 1,532 contracts have traded on the session so far. Calpine Corporation is an independent wholesale power company in the United States. Calpine owns and operates primarily natural gas-fired and geothermal power plants in North America.