Call options were a hot property on Transocean Ltd. (NYSE:RIG - 46.09) last Friday, with roughly 23,000 of these optimistically oriented options crossing the tape during the course of the session. By comparison, the stock typically sees fewer than 6,000 calls change hands during an average day -- and only about 7,500 puts were traded on RIG.

The equity's July 45 call was far and away the most popular strike, with 11,749 contracts exchanged. About 60% of these calls traded at the ask price, suggesting they were purchased, and open interest swelled over the weekend by 3,256 contracts -- confirming that new calls were added here on Friday. Now, RIG's July 45 strike carries peak front-month call open interest of 16,490 contracts.

The volume-weighted average price (VWAP) on the July 45 call checked in at $1.57 last Friday, so most of these call buyers need RIG to rally north of $46.57 by the end of this week. Unfortunately, while the shares have gained an impressive 21% so far in 2012, RIG is down about 0.9% this morning. The stock is retreating from a test of its 80-day moving average, which appears to be resuming its familiar role as technical resistance.

Despite this looming obstacle, speculative investors have grown increasingly optimistic toward RIG in recent weeks. During the past 10 sessions, options players on the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) have bought to open 4.19 calls for every put. Meanwhile, short interest accounts for a slim 1.1% of RIG's float, as very few traders are betting on the stock to decline.