What's going on with Citigroup (C) ?

For awhile now I've been circling around a stock. Citigroup (C) that is. It amazed me that even after a few months of being ranked number 1 (or close to it) it is still number 1 today making it the most actively traded option on the CBOE. With a call option (5) set to expire Jan 22. I simply can't avoid it, even if I wanted to. It shows up everywhere. In the sidebar of my portfolio, in the news and even occasionally it'll pop up during my stock research in a 'what about this stock' way.
Why is this? Well, from a financial sector standpoint the stock is relatively cheap compared to it's competitors and the only stock trading under $5 with a market capitalization of that size.
From a technical standpoint, the stock is about to skyrocket. That's probably why open interest is in the seven (7!) digits around the 5 dollar mark (Jan 22).

Recently, analytics institutions upgraded the stock from hold to buy. From a fundamental standpoint something must be brewing. For anyone interested in the stock or stock option follow news around Citigroup closely on Google news. I'm probably getting the (5) call option for Feb 19 since it's a little cheaper, today.