Whitney Tilson REUTERS/Mike Segar Hedge fund manager Whitney Tilson, who runs Kase Capital, wrote in a group email on Monday that he thinks SodaStream's shares are about to "skyrocket."

"...mark my words. I wouldn’t change a word of my presentation on SODA at the Robin Hood Investors Conference last [October]."

Tilson is long the stock. Shares of SodaStream have tumbled more than 14% since Tilson gave his presentation.

On Sunday, the New York Times published an article about how sales have fallen at SodaStream. The article also pointed out that it's a hassle to replace the SodaStream canister when you can just buy a ready-to-drink soda.

"A) The article focuses on what a hassle it is to replace the SodaStream canister, but I’ve found it to be really easy – just bring it in to any one of 60,000+ stores and walk out with a new one. And what about the hassle of schlepping a bulky, heavy container of soda water bottles through the supermarket, to the car, to your home/apartment, and putting it away?" Tilson wrote in his email.

He continued: "B) Sure, you can buy a liter of sparkling water for 89 cents – but that’s more than TRIPLE the 23-27 cents per liter if you have a SodaStream machine."

It sounds like Tilson is a big fan of the product, too.

We've included his slide deck from the Robin Hood Conference, which was closed to the media, in the slides that follow.