Callon’s stock price has fallen by 36% since the transaction was announced. Shareholders have lost $530 million in value. Callon is paying Carrizo a 25% premium, which is unjustifiable given the inferior assets of Carrizo, and results in the transfer of $240 million in value from Callon shareholders to Carrizo shareholders.

source https://finance.yahoo.com/news/paulson-co-opposes-callon-petroleums-121800564.html?.tsrc=rss