Jack Dorsey, Square's CEO, has been receiving plenty of media attention ahead of the Square IPO, but he may actually end up being one of the biggest risk factors for Square stock when it hits the market.

You see, Dorsey just took on the role as Twitter's permanent CEO on Oct. 5. Potential Square investors want to know if the Twitter cofounder can handle a dual role as Jack Dorsey, Twitter Inc. (NYSE: TWTR) CEO and Jack Dorsey, Square CEO.

In Square Inc.'s (NYSE: SQ) IPO release, the company even acknowledged that the dual roles could cause conflict.

"This may at times adversely affect [Dorsey's] ability to devote time, attention, and effort to Square," the Square IPO filing stated.

The biggest issue is that Dorsey needs to completely overhaul Twitter.

Stagnant user growth, increased competition from Instagram, and difficulty using the service are all issues Dorsey has to address. Turning Twitter around and running Square is a tall order.

Individuals like Steve Jobs and Elon Musk, however, have shown that overseeing two companies can be done. Musk is praised for his ability to handle his dual CEO roles at Tesla and SpaceX, as well as his chairman responsibilities with SolarCity.

Musk recently offered insight into running two companies at the Vanity Fair New Establishment Summit, according to Fortune. When asked at the summit how he manages both roles, Musk simply replied, "I wouldn't recommend running two companies. It decreases your freedom a lot."

This is Dorsey's second time running Twitter. Dorsey was ousted as CEO in 2008 after reportedly leaving work early for yoga classes and fashion shows. Twitter cofounder Evan Williams took over the role, but Dorsey returned in 2011 to as an executive chairman.

Now, Dorsey will list the Square IPO price between $11 and $13 per share. At $13 per share, Square will have a valuation of $4.2 billion.

But before investing in Square, there is a huge, glaring issue with Square stock that investors need to know about…