Softbank Group has agreed to buy British semiconductor maker ARM Holdings for about $31.4 billion in cash, the companies announced Monday. Softbank agreed to pay a hefty premium for ARM, with a price of about $67.28 per ARM share, which is a 42.9 percent premium over the $47.08 closing price as of Friday, the last business day before the deal was announced. The surprise move will help Softbank gain a solid foothold in the Internet of Things, considered the next major wave of development in the enterprise computing business.