Earlier this year, when news broke about Google internally testing a ride-sharing service of its own, some tech executives joked at an event that night that Uber had little to fear; one day it would be able to buy Google outright.

The rapid growth of Uber is difficult to grasp. Five years after launching its taxi app, Uber has entered more than 300 cities in about 60 countries, spurring the creation of copycats and apps for other types of on-demand services nearly everywhere it goes.

Some employees at Uber, now worth about $50 billion to some private investors on paper, already believe it will become the first trillion-dollar company. It could generate about $1.5 billion in net revenue this year, if prior leaked financials are to be believed.

While the bull case for Uber has always been clear, so too have the risk factors, as evidenced by last week’s violent anti-Uber protests in France. The best way to judge those risks is to focus on key questions that CEO Travis Kalanick is already grappling with. (This article is the second in a series by The Information on the big strategic questions facing the most valuable private technology companies.)