Airbnb is experiencing growing pains in some of its major markets across the globe.

Throughout 2017, the number of nights Airbnb hosts listed homes that were available in markets including New York, Paris, Rome, London, Barcelona and Amsterdam increased at a faster rate than listing volume, The Real Deal reports.

While the total number of listings on Airbnb increased by 14% year-over-year, the decline in demand and increase in listing availability in major metros could prove challenging should the slowdown persist, particularly because those metro areas account for a large percentage of its business.

These challenges come amid rumors of a potential initial public offering, though the timing of such a move has yet to be confirmed.

In an effort to shore up its revenue streams, the home-sharing behemoth has added new services to its platform that complement its short-term rentals model. Last November it launched its Airbnb Trips service to help connect travelers with unique experiences listed by local residents in communities across the globe.

Last month Airbnb bid on Wyndham WorldWide Corp.’s European vacation-rental business. In addition, the tech company teamed up with developer Newgard Development Group in October to announce a concept called Niido Powered by Airbnb, which will be a 300-unit apartment building designed with rentals in mind. The apartment is slated to open in Kissimmee, Florida, in 2018.