The year the markets stopped believing in unicorns

Of start-ups poised to go public, four flopped, one nearly collapsed and two are yet to take the plunge. "At the start of this year, it seemed as if the most valuable tech start-ups in the US — Uber, Lyft, Airbnb, Pinterest, Slack, WeWork and Palantir — were on the cusp of triumphant initial public offerings. " But have they lost their magic? Writing in the Financial Times, Elaine Moore explains.