What does the future of wearable devices look like? Whether it’s Fitbit or Nike FuelBands, people are getting more interested in tracking their personal health and activities. Now a cluster of Boston-area startups has emerged, including Quanttus, Bobo Analytics, and Neumitra. Each is working on a health monitor worn on the wrist, and software to make sense of the data. But with Apple and other giants getting into the wearables market, young companies have to be especially careful to differentiate their business from all the noise.

In other innovation news…

-Boston startup Evolv Technologies has new money from Bill Gates and other investors to develop imaging systems using wave-bending metamaterials. The company is a spinout of the controversial patent firm Intellectual Ventures.

-Our deal of the week is a $27 million funding round for Syndax Pharmaceuticals. The Waltham company got started in 2005 and is gearing up for a late-stage clinical trial of its breast cancer drug.

-And finally, as we hit the unofficial end of summer, here are three local companies expected to make a splash before the end of the year. Extreme Reach, which is trying to own video-ad distribution across TV and the Web; Gazelle, where you can sell off your old iPhone and other devices; and Wayfair, in case you need to shop for furniture online starting, perhaps, this holiday weekend.