It’s one of those trends that is hard to say no to: a flurry of monster-sized IPOs debuting this year that have raised billions and will firmly entrench names like Uber, Lyft, and Pinterest on Wall Street. Only now, experts say, the decision to jump into this melee is getting a little murky.

To be sure, some IPOs this year have been big hits already, thanks to a strong economy and stock markets. That has spurred the boards and management of at least some firms to think about this route. After all, there’s a reason they’re calling 2019 the “Year of the IPO”: by some estimates, as many as 150 firms are expected to try them, raising more than $200 billion, the highest amount by far in a decade.

But some experts are encouraging directors to ask, “What’s the rush?” The right timing is critical, and already some public firms didn’t get the valuations they were hoping for, which can create a crisis of confidence among both their investors and customers. And that’s one of the risks that firms rushing into this may face, among a series of stresses that can haunt a company for years. “Directors know they have to manage risk, but they typically have limited infrastructure and resources to assess what they should be doing,” says Karen Dempsey, a partner at the law firm Orrick, which has a large practice in taking firms public.

To date, about half of the 150 firms that IPO’d over the last 12 months have ended up with stock prices trading below their offering price. In contrast, the broad stock market is up more than 11% in the same time frame. The reasons vary, from healthcare firms underestimating the losses their new IPO companies would face to tech outfits losing key executives just before they went public.

Yet, based on most analysts’ forecasts, boards and C-suites that have lined up IPOs don’t appear to be backing down. “When there’s momentum behind IPOs, there’s no question that will impact people’s timing to go forward,” says Tierney Remick, vice chairman of Korn Ferry’s Board and CEO Services practice. “It can be kind of a herd mentality.”

The movement of a company’s daily stock price is out of the board’s hands, of course, but experts worry that some directors can underestimate the talent and time needed to pull off the transition to a publicly traded company successfully. For one thing, listing stock exchanges require boards to add independent directors. The obvious choices are newbies who can help the firm expand into markets or anticipate competitive threats, says Martyn Chapman, head of strategy for Nasdaq Governance Solutions. But the process of finding the right people who can mesh with the existing board is no breeze.

Then there’s the talent issue with management. Experts say directors have to be able to answer difficult questions about the senior executive team. Can the executives identify the firm’s biggest risks on an ongoing basis? Can they find, and effectively use, the key performance metrics that its publicly traded peers use? Perhaps most importantly, do the executives have the agility and leadership skills to run a publicly traded firm?

And now, of course, there’s another question surrounding the Year of the IPO: How are the boards at stumbling IPOs this year responding so far? “You know that conversation is being held [right now] in some boardrooms,” Remick says.