What happened

Shares of ImmunoGen (NASDAQ:IMGN) jumped 10.5% as of the market close on Monday. And the big story of the day for the biotech was... nada. ImmunoGen didn't make any announcements about its pipeline candidates. It didn't make any announcements at all. So why did the stock spike?

Perhaps the most likely reason behind ImmunoGen's big move is a "halo effect" from the J.P. Morgan Healthcare Conference. ImmunoGen isn't scheduled to present at the conference until Wednesday. However, the annual conference kicked off on Monday with lots of biotechs presenting. It isn't unusual for small biotech stocks to enjoy a nice bump from the attention they receive at the healthcare industry's biggest event of the year.

Hands holding test tubes and another hand holding a white cell phone with a purple question mark displayed on it

Image source: Getty Images.

So what

As you might expect, a sizable jump for a stock on no real news isn't anything to hang your hat on. That's especially the case for a highly volatile stock like ImmunoGen.

On the other hand, it's entirely possible that ImmunoGen provides new information at the J.P. Morgan Healthcare Conference that does give investors a reason to be positive about its prospects. Companies like to put their best foot forward at the conference.

ImmunoGen could use some good news after announcing in October that its CFO resigned. The company also reported results in October from a study of mirvetuximab soravtansine in combination with Merck's Keytruda in treating ovarian cancer that disappointed investors.

Now what

Wait 'til Wednesday. That's investors' best approach with ImmunoGen. We'll find out then if the biotech provides information that changes the investing premise for the stock either positively or negatively. 

Assuming there isn't any major announcement, though, the key things to watch with ImmunoGen are its pipeline updates that are on the way. The company expects to report initial data in mid-2019 from its Forward II study cohort evaluating a triple combo of mirvetuximab plus chemotherapies carboplatin and Roche's Avastin. It also anticipates announcing top-line results from the phase 3 Forward I study of mirvetuximab soravtansine in the first half of this year. 

Check out the latest ImmunoGen earnings call transcript.