By clicking “Sign Up”, you accept our Terms of Service and Privacy Policy . You can opt-out at any time by visiting our Preferences page or by clicking "unsubscribe" at the bottom of the email.Access your favorite topics in a personalized feed while you're on the go. download the appSign up to get the inside scoop on today’s biggest stories in markets, tech, and business — delivered daily. Read previewActivist firm Elliott Investment Management has taken a $1.9 billion stake in Southwest Airlines and has pr ...