As per the Securities and Exchange Commission filings on Thursday, Rakesh Gangwal, the billionaire co-founder of InterGlobe Aviation Ltd. and board member, bought around $107 million worth of the company's stock, causing shares of Southwest Airlines Co. to rise. 3.6 million of the carrier's common shares were purchased by Gangwal for about $29 each in a series of transactions that were made public over the course of seven filings.

Gary Kelly, the board's executive chairman, purchased shares in addition to Gangwal. Southwest's stock increased by as much as 4.7% in New York as of 2:40 p.m.Elliott Investment Management, an activist investor, demanded radical changes to the company's leadership and direction, and in July, the company named Gangwal to its board.

Elliott chastised the action, saying last week that it was still committed to calling a special shareholder meeting to allow shareholders to vote on its proposed slate of new members, which would completely restructure Southwest's board.

“I believe changing the Board structure and top leadership beyond what has been already announced, would be counterproductive and not in the best interest of shareholders,” Gangwal said in a statement given by Southwest on Wednesday. "I have invested in the Company's stock with the opening of the trading window for insiders."