$Delta Air Lines (DAL.US)$ options are seeing the heaviest trading volume since May as financial giants pile on positions that could pay off should the share price rebound after the company reports second quarter earnings Thursday.
Total volume rose to about 150,100 contracts as of 2:36 p.m. in New York from about 70,130 a day earlier. The open interest, or the tally of outstanding contracts, are heavily concentrated on cal...