This company was only responsible for research and development.
It had no factory.
It could support itself merely on the revenue from patent licensing, with an annual surplus of hundreds of millions of dollars, and the entire company had almost no debt and no shortage of money. The difficulty of proposing an acquisition for a company that didn't lack funds could be imagined.
If it were anyone else,
it would be nearly impossible to acquire it. Even if they offered two to three times the price, the company might not even take a second glance, and without the approval of big clients and shareholders such as Apple, Qualcomm, and Samsung, they shouldn't even think about it.
It was also because these world-class companies held stocks in ARM.