Ride-hailing giant set to trade on Nasdaq. : Grab Holdings, Southeast Asia’s most valuable startup, is going public in the US through a merger with blank-check company Altimeter Growth Corp in what is the largest-ever deal of its kind. The Singapore-based startup is set to have a market value of about $39.6 billion after the combination with the special purpose acquisition company of Brad Gerstner’s Altimeter Capital Manage­ment, the firms said on Tuesday.