Grab Holdings Inc. said it would go public on the Nasdaq Stock Market by merging with a special-purpose acquisition company, securing a near-$40 billion valuation in a new milestone for the SPAC boom that has swept U.S. financial markets.

The $39.6 billion deal to list Grab, a ride-hailing, food-delivery and digital-wallet group that operates across much of Southeast Asia, is by far the biggest involving a blank-check company and means Grab’s valuation has more than doubled in just 18 months. The merger also comes alongside a $4 billion-plus fundraising, which is the largest-ever share sale by a Southeast Asian company in the U.S.

Singapore-based Grab said Tuesday it would merge with Altimeter Growth Corp. , a SPAC sponsored by Altimeter Capital, of Menlo Park, Calif., confirming an earlier report by The Wall Street Journal.

The Grab merger adds to a frenzy of SPAC-related deal making. A record $99 billion has been raised in the U.S. by a total of 306 SPACs this year, according to SPAC Research data. Some 435 of these vehicles, which raise funds in an initial public offering and then look for a business to combine with, are still seeking a merger target.

The SPAC market has cooled off in recent weeks, with the pace of new issuance slowing substantially and many of the vehicles trading lower. The Securities and Exchange Commission also has stepped up its scrutiny of blank-check deals.