https://www.reuters.com/article/us-uber-ipo-kalanick/defiant-uber-co-founder-kalanick-shows-up-for-stock-market-premiere-idUSKCN1SG1Q0 >Travis Kalanick, the co-founder of Uber Technologies Inc who stepped down as CEO in 2017 amid a string of scandals, showed up for the ride-hailing giant's stock market debut on Friday even though Uber had not invited him to join executives on the balcony of the New York Stock Exchange to ring the opening bell.