What: Shares of Juno Therapeutics (JUNO), a mid-cap biotech with a focus on chimeric antigen receptor to train T cells, or CAR-T therapy, treated its investors to yet another strong month. Shares traded more than 26% higher in October, according to data from S&P Capital IQ.

JUNO Chart

So what: Although the company didn't release any news during the month, Juno Therapeutics saw its shares jump after an analyst at FBR & Co. issued a bullish report on the company. In addition, Juno will be presenting data at the upcoming American Society of Hematology meeting, which starts in early December, so investors could be bidding up the stock ahead of it.

Regardless of the reason, shares have bounced back strongly from their September lows, and investors who got in at Juno's IPO are currently sitting on a strong 42% gain. 

Now what: Juno Therapeutics' stock has been extremely volatile since news broke about its 10-year collaboration deal with biotech blue-chip Celgene (CELG). The collaboration gives Celgene the option to commercialize Juno programs outside North America and gives both companies the ability to co-promote certain programs around the globe. Juno also received an up-front payment of $150.2 million as well as $849.8 million in proceeds from Celgene's stock purchase in Juno, which valued the deal at $1 billion.

Investors initially cheered the announcement by sending Juno's stock up huge, but shares came crashing back to Earth as investors sold off the entire biotech sector. 

Over the long term, this deal should give Juno investors plenty of reasons to be optimistic, as Celgene has a long history of success in the cancer market and a war chest of cash that it could use to make additional investments in the collaboration if needed. Celgene also has a successful commercial team in place already so any new therapies that are produced from this agreement could potentially be launched quickly. 

Like shares of any other money-losing biotech, Juno Therapeutics' shares are likely to remain extremely volatile for years to come, so investors should be mentally preparing themselves for a wild ride.