What happened Seattle Genetics (NASDAQ: SGEN) shareholders outpaced a declining market in September as the stock jumped 24% compared to the S&P 500's 3.9% drop, according to data provided by S&P Global Market Intelligence. That surge added to a broader rally for the biotech company; its shares are up by more than 70% so far in 2020. Image source: Getty Images. So what Early in the month, investors celebrated the news that Seattle Genetics is partnering with Merck & Co (NYSE: MRK) in two major oncology development programs. Merck will jointly develop and commercialize the biotech's breast cancer tumor treatment, and will assist it in its attempts to broaden the reach of its cancer-fighting drug, Tukysa. The two collaboration agreements included more than $700 million in upfront payments to Seattle Genetics, with the total size of the deal potentially exceeding $4 billion. Now what Merck has taken a 50% position in any future costs and profits for Seattle Genetics' breast cancer treatment, and has received exclusive rights to commercialize Tukysa outside of the U.S., Canada, and Europe. The company also purchased $1 billion of Seattle Genetics stock for $200 per share. Investors pushed the stock above that level last month, an indication that they see the potential for even more value to come from this partnership in the coming years. 10 stocks we like better than Seattle GeneticsWhen investing geniuses David and Tom Gardner have 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.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Seattle Genetics 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 September 24, 2020 Demitri Kalogeropoulos has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Seattle Genetics. The Motley Fool has a disclosure policy.Source