The biotech rollercoaster ride continues in Boston. On the one hand, Natick-based Karyopharm Therapeutics has just raised $109 million in an initial public offering; the cancer drug maker is the ninth local biotech to go public this year. On the other hand, at least three public companies are struggling: Ariad Pharmaceuticals is laying off 40 percent of its staff after pulling its leukemia drug off the market, Curis has hit an FDA snag with its experimental cancer drug, and Immunogen’s drug for lung cancer has flopped in a clinical trial. Just a reminder that biotech drugs are always a risky business.

In other innovation news…

— You might have heard about that Twitter IPO. The social media company has big plans locally, having acquired Cambridge startups Crashlytics and Bluefin Labs earlier this year. (The value of those deals just went up.)

— Not to be outdone, Facebook has finally acknowledged that it’s building an engineering team in the Boston area — most likely, in Cambridge.

— Our startup of the week is CyPhy Works, led by iRobot co-founder Helen Greiner. The Danvers company has raised $7 million in new venture financing to build out its drone technology.

— And lastly, now that the hype of “big data” has worn off, a real industry is starting to get built. Xconomy is convening experts including Mathematica creator Stephen Wolfram and the MIT Media Lab’s Sandy Pentland for our D2 conference on the future of data and devices. It’s all happening in Boston on November 21.