While standard share sales can move quickly through approval, it’s common for SEC staff to spend more time examining offerings that involve new types of structures or products. It’s possible regulators simply want a better understanding of how Spotify’s listing will work. The agency declined to comment. The company’s plan poses an early test for how far SEC Chairman Jay Clayton is willing to go to boost new U.S. listings.

https://www.bloomberg.com/news/articles/2017-08-21/sec-is-said-to-study-spotify-plan-to-bypass-ipo-in-nyse-listing