Rachel Metz: Fitbit CEO on Wearable Gadgets, the Future of Sensors, and Wall Street

In the six years since Fitbit began selling its first fitness tracker, a $100 clip-on device that used a growing flower on its tiny display to indicate how active you’d been, the market for wearable gadgets has changed tremendously.

Companies large and small have flooded the market with all kinds of fitness trackers, smart watches, and other wearable devices. According to technology market researcher IDC, between July and September of 2015, 21 million wearables were shipped out, about triple the number from a year earlier.