Not much has gone right for Citigroup (NYSE:C) so far in 2014. There's been a debacle in its Mexico banking arm. It's dividend and share-buyback plans were rejected by the Federal Reserve. And the market has just generally soured on the global lender.

But there's still reason to be bullish on Citi's stock. One of the most obvious reasons is valuation: The stock trades at a considerable discount to both book value and tangible book value. And while it'd be hard to call the tenure of CEO Michael Corbat a smashing success so far, he has big plans for the bank and has only been in the top role since late 2012.

Whitney Tilson, managing partner of hedge fund Kase Capital is one of the Citigroup bulls out there. In the video below, he explains why Citi is a position in Kase's portfolio that he's confident about.

A transcript follows the video.

Tilson: Citigroup and AIG are actually very similar themes, in my opinion. Both companies basically went bankrupt and got bailed out by the government in the crisis; terribly tainted, terrible headlines.

Both have cleaned up, gotten rid of a lot of the bad businesses, they've run off their bad book of business, yet I think the stocks are still tainted by what happened during the crisis. Both are trading at a discount to book value, and both are fabulous global franchises that are worth at least 1x book, probably 1.2x book.

Citigroup, though, is about half the size position for me as AIG, for two reasons. I have a little more confidence in Benmosche and the turnaround and cost-cutting, and so forth. Probably a little bit better business, and the stock is trading at a better discount to book -- so cheaper stock, better business, better management -- that's why it's a bigger position.

But Citigroup, I would say it's probably got 20% upside, when some of the current short-term noise passes. It was obviously a big disappointment when they didn't get approval to be returning capital, and I think near-term catalysts for the stock were delayed, and a lot of short-term oriented folks just dumped the stock.

But surprisingly, the stock has sort of held up pretty well, actually, just because it's so cheap.

Koppenheffer: And the capital is there, right?

Tilson: Yes. To some extent, forcing a bank that ran out of capital to hold more excess capital ...

Koppenheffer: It's not a terrible idea.

Tilson: As someone who, most importantly, prefers to sleep well at night -- that's a good thing.

Matt Koppenheffer owns shares of American International Group and Citigroup. The Motley Fool recommends American International Group. The Motley Fool owns shares of American International Group and Citigroup and has the following options: long January 2016 $30 calls on American International Group. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.