Broncus Holding Corp.’s shares tumbled more than 20% on its first trading day on Friday, Sept. 24, in Hong Kong. It raised HK$1.55 billion (US$199.1 million) at HK$18.70 a share, the top end of its target range. Nearly half of the proceeds will be used for the R&D and commercialization of its two core interventional pulmonology products: the Intervapor system and the RF Generator + RF Ablation Catheter (RF-II).