There's never a dull day for 90 year old billionaire investor Kirk Kerkorian. In addition to trimming his massive GM stake, his Tracinda Corp Tracinda is planning a cash tender for up to 15 million shares of MGM Mirage (MGM) at a price of $55. MGM is up 10% at just above $54. Could there be more upside? At least one firm is very bullishing. STFL today lifted its price target on MGM from $50 to $65.