He's been selling the old shares because he has to. They expire if he didn't.
According to the SEC filing, Parker paid about $10.7 million to exercise options and acquire 505,375 shares on Thursday. The options were from the 2005 merger of US Airways and America West and
were due to begin expiring later this month. That boosted his stake to more than 2 million shares, and he sold 702,375 shares for more than $24.1 million on the same day.
A company spokesman said that about half of Parker’s profit came from selling shares that he bought in 2008 as a show of confidence at a time when the airline industry was struggling with skyrocketing fuel costs.
http://skift.com/2014/02/15/american-airlines-ceo-doug-parker-nets-13-4-million-profit-in-stock-sales/
“Today the Company reported that CEO Doug Parker has exercised and sold 113,000 stock appreciation rights (SARs). Doug received these SARs (similar to stock options) in April 2006, August 2008 and April 2009 when he was CEO of US Airways. These SARs expire over the next 12 months, which means they expire worthless if they are not exercised and sold.
“To facilitate the exercise and sale of this equity before expiration, Doug entered into a 10b5-1 plan May 20, 2015 that lays out a specific date each month for the next year whereby Doug will exercise and sell these SARs. The award prices range from $3.10 to $38.44 per share, which is the price Doug will pay to exercise the SARs, which will then be sold in the open market. How much these SARs are ultimately worth will depend on the share price of AAL stock at the time the shares are sold.
“Doug has a large holding in AAL that has been publicly disclosed and remains extremely positive about the future of American.”
http://aviationblog.dallasnews.com/2015/06/american-airlines-ceo-doug-parker-nets-4-1-million-in-stock-sale.html/