Zendesk Inc. /zigman2/quotes/209571012/composite ZEN +0.50% shares plunged as much as 7% in after-hours trading Thursday after the software company reported fiscal first-quarter earnings that missed Wall Street estimates, and it withdrew full-year 2020 guidance because of uncertainty surrounding the coronavirus pandemic. Zendesk reported a loss of $42.8 million, or 38 cents a share. Revenue climbed to $237.5 million from $181.5 million a year ago. Analysts surveyed by FactSet had expected earnings of 6 cents a share on sales of $237 million. Zendesk shares are down 8% in the last year. The broader S&P 500 index /zigman2/quotes/210599714/realtime SPX +0.24% is down 0.2% in the last year.