HONG KONG -- When the prospectus for Luckin Coffee's New York listing was published last May, nowhere was it more intensely scrutinized than in the offices of Warburg Pincus, high above Grand Central Station. The investment firm knew the personnel behind Luckin, a downmarket Chinese coffee chain, very well. The fund had invested in China Auto Rental, an online car hire business founded by Lu Zhengyao, Luckin's chairman. Several members of Luckin's board had also worked at CAR. David Li, another board member, had been head of Warburg's own China team between 2012 and 2016, when he left to start his own private equity company, Centurium Capital. It was Li who had first introduced Lu to the people at Warburg.