I'm reasonably familiar with it having owned it in the past. With it being an offshore driller, a much more expensive method of getting oil as compared to more conventional methods, their earnings can be more difficult to predict during times of substantially fluctuating crude oil prices. In other words, when oil is relatively cheap, the demand for offshore drilling can significantly decrease, and vice versa when the oil prices are higher.
The biggest factor, however in recent weeks as far as the stock price goes, has very little to do with any of that. With Transocean's stock having traded over much of the past 20 years in the $20-$160 range, a huge portion of the investors in the stock have had large unrealized losses. People don't do their tax planning for a particular tax year in February. People don't do it in September. They are, however, going to do it before year-end. As the Christmas holidays approach, people start looking for things they can do to reduce their tax burdens. By Christmas, most of this year-end tax planning is over as investors dump holdings with substantial losses so they the can use the losses to offset gains elsewhere, or either harvest them for future years. Dumping RIG in December, for many of their stockholders, was the thing to do, even if they liked the company and wanted to buy it back in 30 days to avoid a wash sale. All of this creates a very unusual downdraft in the stock as the large supply of sell orders hits at one time, typically pushing such a stock to well below its fair valuation.
When January arrives, the year-end selling is long over. Any that had any near-term need to sell that stock likely has already done it. What then happens? You have a significant updraft in the stock price, one that can be very rewarding for those that know how to take advantage of these annual year-end stock valuation phenomenons. This year we've seen similar stock movements in many of the tech stocks. RIG had a similar jump from 12/21 to 1/22. Tax policy causes people to do the same things year after year.
I've utilized this stock trading technique for years; even used to have a contest in my office where everyone would put in $10 and pick a stock that could benefit from the "year-end effect." The stock that goes up the largest percentage from the entry date until January 10th would win all of the money.
I annually look for a stock or two to buy that uses this strategy. This year I bought C3AI (AI-NYSE). I bought it in December at $10.50. It's up another $2 per share today at $22.