According to many Wall Street insiders, 2019 was supposed to be a banner year for initial public offerings. A number of high-profile startups have chosen this year as the time to go public, and investors have had great expectations for them. But so far, they’ve been disappointed. Uber and Lyft, for example, began to fade not long after their IPOs. 

They hope that things go differently for Slack. As of June 20, investors will be able to purchase shares of Slack, the workplace collaboration tool that was co-founded in 2009 and is now valued at $7.1 billion. Slack today has more than 88,000 paying customers, which portends great potential for the company and its founder, Stewart Butterfield. And yet, according to The New York Times, there are still doubts about whether such a startup can be competitive long-term against tech giants like Microsoft, Cisco, and Facebook—all of which make similar tools.

“There is one set of skills in making technology find the lips of all young developers around the world,” said Michael Facemire, an analyst at Forrester. “There’s another set of skills to sell that into the enterprise.”

Slack has a couple of difficulties to worry about as its IPO date nears. One is the staying power of the product itself; another is the erratic personality of Butterfield, the company’s founder. Butterfield’s outspoken nature has gotten him into PR trouble on multiple occasions. He’s famous for buying a snarky full-page newspaper ad to taunt rival Microsoft, as well as for firing off expletive-laden opinions about Donald Trump on social media. To appeal to investors, he may need to rein it in.

Despite all the question marks surrounding Slack, there are many on Wall Street with high hopes for the company’s viability. Many have pointed to Slack not only as a potentially huge success, but also as a bellwether for the future performance of Silicon Valley as a whole.

That’s a lot of pressure for Butterfield and his team, but they will try to live up to it.

“The success of the business, the happiness of the employees, its impact on customers—all that stuff,” the founder said. “It can be a lot to manage.”