Cloud computing firm Zuora jumped almost 43 percent in its first day of trading on the public market. The stock opened at $20 a share, above its Wednesday night pricing of $14 a share, and held those gains to close flat on Thursday at $20. The company listed its $154 million initial public offering on the New York Stock Exchange under the ticker symbol "ZUO." Zuora priced its 11 million shares at $14 on Wednesday, above a revised expected range of $11 to $13. That implies a valuation of just...