Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of bluebird bio (NASDAQ:BLUE), a clinical-stage biopharmaceutical company developing gene-based therapies to treat genetic disorders, surged higher by as much as 60% after reporting encouraging initial data from its HGB-205 study involving LentiGlobin as a treatment for beta-thalassemia major, a blood disorder that results in the destruction of red blood cells and lead to anemia, at the annual European Hematology Association meeting in Italy.

So what: According to bluebird's data release, the first two clinical patients in its HGB-205 have been blood transfusion independent since day 10 and 12, respectively, following treatment with LentiGlobin. Furthermore, no drug-related adverse events were noted in either patient, which is always a concern when you're dealing with gene-modifying therapies. Bluebird anticipates reporting additional data later this year on these patients as well as an expanded 15 patient beta-thalassemia trial.

Now what: Again, we have incredibly encouraging data that after less than two weeks patients who are in constant need of transfusions have been transfusion-free for months. As noted from its original LG001 study, its third subject has remained transfusion-free for a full six years! The safety profile, though, is what's more impressive to me as gene therapies can often come with notable side effects. While I believe there's merit for upside today, I'd also encourage investors not to uncork the champagne bottle just yet after a very small sample size of patients has shown a response. With a valuation that topped $1 billion this morning for a clinical-stage company I'd surmise that traders are allowing their emotions to get the best of them. Feel free to add bluebird to your watchlist, but I'd suggest monitoring it from a very safe distance for the time being.