Shares of struggling social media site Twitter (TWTR – Analyst Report) are down another 3.5% today, bringing the stock below all-time low levels. While some viewed the recent assignment of cofounder Jack Dorsey to the full-time CEO position would bring some much needed change to the company, it’s actually news about Dorsey that is helping drive this stock down today.

Also read: Who is Jack Dorsey?

The problem today seems to be stemming from this profile by the Wall Street Journal. The issue with Dorsey is that he’s a very busy man. In addition to his time at Twitter, he also serves as CEO of Square (SQ – Snapshot Report), a mobile payment solutions company he also helped found.

According to the WSJ, Dorsey is known to work up to 18 hours per weekday, spending half the day at each company. The Wall Street Journal also says that, “current and former Twitter employees say he is known to abruptly get up at the designated end time of a meeting, simply saying, ‘I’ve got to go.’”

Investors may be overreacting to this news. Some leaders have seen great success working at two companies at the same time, such as Steve Jobs when he served at both Apple (AAPL – Analyst Report) and the now Disney (DIS – Analyst Report) -owned Pixar Studios. Right now, Tesla Motors (TSLA – Analyst Report) front man Elon Musk splits his time between the electric car company and SpaceX.

With that said, this is exactly the kind of news that investors were worried about when Dorsey was named CEO and said he would remain at Square. Twitter isn’t Apple and no one is Steve Jobs, so it could very well be too much for the 39-year-old bachelor.

Right now, Twitter needs a lot of work, and it makes sense that investors would wonder whether Dorsey can put in the amount that’s needed. The company has been making moves recently, as it recently announced plans to cash in on unregistered users with a new ad strategy.

As a site, Twitter has been struggling to grow. Cashing in on visitors to the site that don’t have accounts is one way to bring in revenue without actually growing your user base. However, the past week’s trading activity seems to indicate that investors aren’t impressed.