Just because a business does not make any money, does not mean that the stock will go down. 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. Having said that, unprofitable companies are risky because they could potentially burn through all their cash and become distressed.

So should Prime Medicine (NASDAQ:PRME) shareholders be worried about its cash burn? In this article, we define cash burn as its annual (negative) free cash flow, which is the amount of money a company spends each year to fund its growth. We'll start by comparing its cash burn with its cash reserves in order to calculate its cash runway.

Does Prime Medicine Have A Long Cash Runway?

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 March 2026, Prime Medicine had US$135m in cash, and was debt-free. Looking at the last year, the company burnt through US$159m. Therefore, from March 2026 it had roughly 10 months of cash runway. 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. You can see how its cash balance has changed over time in the image below.

How Well Is Prime Medicine Growing?

At first glance it's a bit worrying to see that Prime Medicine actually boosted its cash burn by 42%, year on year. At least the revenue was up 4.9% during the period, even if it wasn't up by much. Considering both these factors, we're not particularly excited by its growth profile. Clearly, however, the crucial factor is whether the company will grow its business going forward. So you might want to take a peek at how much the company is expected to grow in the next few years.

How Hard Would It Be For Prime Medicine To Raise More Cash For Growth?

Given the trajectory of Prime Medicine's cash burn, many investors will already be thinking about how it might raise more cash in the future. Companies can raise capital through either debt or equity. Many companies end up issuing new shares to fund future growth. By comparing a company's annual cash burn to its total market capitalisation, we can estimate roughly how many shares it would have to issue in order to run the company for another year (at the same burn rate).

Since it has a market capitalisation of US$518m, Prime Medicine's US$159m in cash burn equates to about 31% of its market value. That's fairly notable cash burn, so if the company had to sell shares to cover the cost of another year's operations, shareholders would suffer some costly dilution.

Is Prime Medicine's Cash Burn A Worry?

Even though its increasing cash burn makes us a little nervous, we are compelled to mention that we thought Prime Medicine's revenue growth was relatively promising. Summing up, we think the Prime Medicine's cash burn is a risk, based on the factors we mentioned in this article. On another note, Prime Medicine has 5 warning signs (and 3 which are a bit unpleasant) we think you should know about.

Of course Prime Medicine may not be the best stock to buy. So you may wish to see this free collection of companies boasting high return on equity, or this list of stocks with high insider ownership.

This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.