It worked the first time -- Elliott Management might be hoping the playbook works again. It's now rebuilding a more than $2 billion stake in Softbank and calling for a $15B buyback after pushing successfully for changes in early 2020. At the center of the push is that Softbank as a whole’s market value is far less than the sum of its parts: its 90% stake in Arm alone is worth more than $100 billion, far more than its market cap of around $85 billion.