LONDON, Aug 22 (Reuters Breakingviews) - The dangers of investing in Arm are easy to find in the pages of its initial public offering document, disclosed late on Monday. Yet the artificial intelligence-based opportunities for SoftBank Group's (9984.T) chip designer are based more on hope than financial fact. That undermines its chances of hitting a hoped-for listing valuation north of $60 billion. The optimistic case for UK-based Arm is that it sits at the center of a long-term AI boom. Arm’s fundamental designs allow other semiconductor and tech companies, such as Nvidia (NVDA.O) and Alphabet (GOOGL.O), to build energy-efficient chips...