TOKYO -The roaring success of Arm Holdings' stock market debut makes it much easier for owner SoftBank Group to revert to its natural state - acquisition-hungry. Shares in the British chip designer jumped almost 25 percent on its first day of trade - propelling its value to more than double the $32 billion SoftBank paid to acquire it in 2016. The tech investment behemoth raised nearly $5 billion from Arm's offering while retaining 90.6 percent of the firm. READ: SoftBank's Arm soars nearly 25% in market debut to $65-B valuation Known for debt-fueled acquisition sprees, SoftBank founder and CEO Masayoshi Son flagged in June that the company was shifting back into "offense mod...Keep on reading: Arm’s stellar listing sets the stage for more SoftBank acquisitions