Option bulls bombarded Zipcar Inc (NASDAQ:ZIP) Friday with traders gambling on even more upside for the soaring stock. At the time of this writing (November 9 12:04 p.m.) the stock had seen close to 1 300 calls cross the tape -- about 19 times its average intraday call volume. For comparison fewer than 600 ZIP puts have changed hands thus far. Digging deeper long-term investors have honed in on the now at-the-money May 7.50 call which has seen close to 400 contracts cross the tape. The majority of the calls have exchanged at the ask price suggesting they were ...