What happened

Shares of connected fitness product company Peloton Interactive (PTON -5.71%) fell sharply on Thursday, declining more than 5% as of 1 p.m. EDT.

The growth stock's sharp drop was likely driven primarily by a bearish note from short-seller Citron Research Thursday morning.

A man riding a Peloton bike

Image source: Peloton.

So what

Acknowledging on Twitter that Peloton has a "great product at the right time," Citron warned that investors shouldn't "count out [Apple]." Citron pointed to recently published Apple (AAPL 0.70%) patents, including one related to the company's upcoming Peloton-like Apple Fitness+ service. 

The patent shows machine learning and artificial intelligence used for customized workouts and a "burn bar" that will be displayed on users' Apple smartwatches.

Now what

Investors should take Citron's research with a grain of salt. The short-seller firm isn't always right and, in some cases, has been very wrong.

There isn't a specific launch date for Apple's new workout subscription service, but the company has said it is coming late this year.