What happened Shares of gene therapy company Bluebird Bio (NASDAQ: BLUE) fell by 10.7% through the first four full days of trading this week, according to data provided by S&P Global Market Intelligence. Bluebird's shares hit the skids last Tuesday immediately after the company provided a corporate update ahead of its presentation at the 40th Annual J.P. Morgan Health Care Conference. The key issue concerning investors appears to be the biotech's financial health. With two potential regulatory approvals and commercial launches coming down the pike later this year, Bluebird's most recent cash, cash equivalents, and marketable securities balance of approximately $442 million probably won't be sufficient to meet its short-term financial needs. Image source: Getty Images. So what On a positive note, Bluebird said it plans on exploring the sale for the priority review vouchers expected to be issued with the U.S. approvals of its gene therapies known as beti-cel and eli-cel, respectively. A sale ought to bring in approximately $150 million to $200 million in non-dilutive funding before the end of the year, according to management. The big deal is that these additional funds should extend Bluebird's cash runway into 2023. Now what Is Bluebird's stock worth picking up on this latest weakness? Although the biotech stands a decent shot at garnering regulatory approvals for both beti-cel and eli-cel later this year, these novel gene therapies might take a few years to gain traction in the marketplace. These are groundbreaking therapies that will come with unique logistical hurdles, after all. In short, it might be best to take a wait-and-see approach with this top gene therapy stock for now. 10 stocks we like better than Bluebird BioWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Bluebird Bio wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of January 10, 2022 George Budwell has no position in any of the stocks mentioned. JPMorgan Chase is an advertising partner of The Ascent, a Motley Fool company. The Motley Fool recommends Bluebird Bio. The Motley Fool has a disclosure policy.Source