By Syndicated Content By Anshuman Daga SINGAPORE (Reuters) â Singaporeâs Grab more than doubled its valuation to $40 billion in about a year as part of the worldâs largest SPAC deal, but maintaining that level after its U.S. debut will be a test not only for investors but also for firms eyeing similar listings. Earlier this month, Southeast Asiaâs biggest ride-hailing and delivery firm, agreed to merge with a special purpose acquisition company (SPAC) backed by Silicon Valley investor Altimeter Capital Management. [L1N2M609X] The backdoor Nasdaq listing will see nine-year-old Grab raise over $4 billion, a record U.S. offering from Southeast Asia.