Aetna rose in strong volume early Tuesday, leading a sector rally, after it said it expects that its total medical membership at the end of 2014 would top its prior estimate of 23.4 million members. Aetna also affirmed revised full-year 2014 earnings per share guidance, initially given Dec. 12, saying it will come in at the upper end of a $6.60-$6.70 range and revenue will be $57 billion to $58 billion.