Cvent merged with special purpose acquisition company Dragoneer Growth Opportunities and went public on the Nasdaq in December. Shares opened Monday 62 percent lower, against a 28 percent fall for the exchange as a whole. American Express Global Business Travel merged with SPAC Apollo Strategic Growth Capital to go public May 31 on the New York Stock Exchange. Shares were off 5.4 percent Monday morning while the NYSE Composite had fallen 5.3 percent. Altitude Acquisition Corp., a SPAC co-founded by Teplis Travel CEO Gary Teplis, on . . .