What happened

Novocure Ltd. (NASDAQ:NVCR) stock jumped 16.3% in September, according to data from S&P Global Market Intelligence. For context, the S&P 500 returned 0.6% last month.

Shares of the maker of a device for treating brain cancer with electric fields have given back nearly their entire September gain already this month. Through Oct. 10, Novocure stock is down 14.2%. Unlike last month's upward movement, which we can largely attribute to company-specific news, October's sell-off appears to be due to the notable downturn in the broader market. The S&P 500 and the tech-heavy Nasdaq Composite are down 4.4% and 7.8%, respectively, so far this month. High-flying stocks, such as Novocure, have been hit particularly hard. Nonetheless, the stock is still up a whopping 123% in 2018. 

Man sitting at desk wearing Novocure's Optune, which appears like netting on his head and includes an over-the-shoulder attachment attached to the head device.

Image source: Novocure.

So what

We can attribute Novocure stock's hardy September performance to several factors. First, it's probably safe to assume it was in part a continuation of the upward trend it's been charting for some time thanks to investor optimism about the company's novel therapy for treating solid tumors with electric fields, Tumor Treating Fields, or TTFields. Novocure's Optune device is currently approved by the U.S. Food and Drug Administration (FDA) to treat adults with glioblastoma, the most common primary brain cancer in adults and one of the most difficult cancer types to treat. Investors are hopeful that the company's addressable market will expand to include other types of cancers

Novocure stock also got a boost from several specific catalysts during the month:

  • On Sept. 5, the stock shot up 5.3% after the company announced promising results from its phase 2 trial in malignant pleural mesothelioma, which is a rare cancer primarily caused by inhaling asbestos fibers into the lungs. Results showed "a significant extension in median overall survival among patients treated with Tumor Treating Fields plus standard of care chemotherapy compared to historical control data of patients who received standard of care chemotherapy alone."  

  • On Sept. 12, the stock popped 3.8% after Novocure announced that it granted Shanghai-based Zai Lab an exclusive license to commercialize its Tumor Treating Fields in China, Hong Kong, Macau, and Taiwan.

  • On Sept. 25, the stock rose 3.9% after the company announced that results from its phase 2 trial in mesothelioma (first bullet point) would be highlighted in a presentation at the International Association for the Study of Lung Cancer (IASLC) World Conference on Lung Cancer on Sept. 25 in Toronto.

Now what

Novocure is slated to report its third-quarter results on Thursday, Oct. 24, after the market open. So, investors should soon be getting material news about the Jersey-based (think Channel Islands, not The Sopranos) company.

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.