The price target represents a downside from the stock's $21.70 closing price on Tuesday.
"Virtually all leading indicators of growth are negative. App monthly active users, daily active users, app downloads, number of app sessions, total time spent in app, and Google searches have all been declining in recent quarters while these same data for major cloud vendors have been much more positive," analyst Zane Chrane said.
Headwinds for the company include a crowded file storage landscape as well as the company's decision to raise prices on its Plus plan in May.
"We believe the natural market structure for collaboration tools is likely to be a monopoly or duopoly, in which Microsoft and Slack are the only two viable contenders," Chrane wrote. "This, along with the fact that Dropbox does not have a fully developed enterprise sales organization puts them at a significant disadvantage in a market where network effects give first movers a huge advantage."
Dropbox was down 3.3% to $20.99 in trading Wednesday.