What happened?

Shares of Orchard Therapeutics (NASDAQ:ORTX) are up by 16.9% as of 12:27 p.m. EDT on Tuesday after rising by as much as 32.9% earlier today. The biotech company did not report any news that served as a catalyst for these massive gains, though, so what gives?

Here is a possible explanation. Orchard Therapeutics' stock was down by more than 60% year to date before today, and perhaps investors who finally felt as though the price was right bid up the company's shares.

Hand drawing an upward-bound graph on a chalkboard.

Image source: Getty Images.

So what

Stock prices fluctuate, sometimes by massive amounts, from one day to the next. These moves don't always make sense, and for investors focused on the long term, they rarely matter. Focusing on the fundamentals of a company rather than the day-to-day changes of its stock price is a much more fruitful endeavor. With that in mind, here is a short overview of Orchard Therapeutics. The company focuses on developing gene therapies for rare diseases.

The biotech's sole product on the market is called Strimvelis, which the European Medicines Agency approved back in 2016; the medicine isn't approved in the U.S. at this time. Strimvelis is used to treat severe combined immunodeficiency due to adenosine deaminase deficiency, a rare genetic disorder. This product does not generate much by way of revenue, however. During the first quarter, Orchard Therapeutics' net sales came in at $597,000, and the company reported a net loss of $47.5 million.

Now what

While Orchard Therapeutics does have several other candidates in its pipeline, the company remains a risky bet. There are far more attractive biotech stocks to consider buying out there, and it'd be wise to steer clear of Orchard Therapeutics for now.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.