The reasons: Rule breaking at Zenefits; PayPal is facing increasing competition from the old money companies like Visa; Yelp cries for help after it posts its fourth loss in a row and finally Imagination Technologies' CEO Hossein Yassaie "stepped down" after 18rs which shows there is always a price to pay when things slow down.
Gone are Zenefits CEO Parker Conrad, Imagination Technologies CEO Hossein Yassaie, Yelp CFO Rob Krolik and Paypal CTO James Barrese. All resigned, although it has been strongly intimated in each case that the resignation was not necessarily voluntary. And while it's not exactly new that some C-suite execs have decided to spend more time with their families, what is remarkable in these cases is that they come from established businesses facing a financial downturn. The market is clearly angling for a tech shakeout and these four may be the first signs of it. Others are almost certainly on their way, with Yahoo CEO Marissa Mayer and Theranos CEO Elizabeth Holmes unlikely to survive 2016.
http://www.theregister.co.uk/2016/02/09/2016_tech_shakeout_csuite_exits/