There's no doubt that money can be made by owning shares of unprofitable businesses. For example, although software-as-a-service business Salesforce.com lost money for years while it grew recurring revenue, if you held shares since 2005, you'd have done very well indeed. Nonetheless, only a fool would ignore the risk that a loss making company burns through its cash too quickly.

So, the natural question for SELLAS Life Sciences Group (NASDAQ:SLS) shareholders is whether they should be concerned by its rate of cash burn. For the purpose of this article, we'll define cash burn as the amount of cash the company is spending each year to fund its growth (also called its negative free cash flow). First, we'll determine its cash runway by comparing its cash burn with its cash reserves.

See our latest analysis for SELLAS Life Sciences Group

A company's cash runway is the amount of time it would take to burn through its cash reserves at its current cash burn rate. In September 2024, SELLAS Life Sciences Group had US$21m in cash, and was debt-free. Looking at the last year, the company burnt through US$33m. That means it had a cash runway of around 8 months as of September 2024. To be frank, this kind of short runway puts us on edge, as it indicates the company must reduce its cash burn significantly, or else raise cash imminently. The image below shows how its cash balance has been changing over the last few years.

SELLAS Life Sciences Group didn't record any revenue over the last year, indicating that it's an early stage company still developing its business. So while we can't look to sales to understand growth, we can look at how the cash burn is changing to understand how expenditure is trending over time. As it happens, the company's cash burn reduced by 11% over the last year, which suggests that management may be mindful of the risks of their depleting cash reserves. While the past is always worth studying, it is the future that matters most of all. For that reason, it makes a lot of sense to take a look at our analyst forecasts for the company.

While SELLAS Life Sciences Group is showing a solid reduction in its cash burn, it's still worth considering how easily it could raise more cash, even just to fuel faster growth. Issuing new shares, or taking on debt, are the most common ways for a listed company to raise more money for its business. Commonly, a business will sell new shares in itself to raise cash and drive growth. By looking at a company's cash burn relative to its market capitalisation, we gain insight on how much shareholders would be diluted if the company needed to raise enough cash to cover another year's cash burn.