The stock's high valuation raises the risk of a post-earnings sell-off this week.Arm Holdings (ARM 0.13%) has been a rising star in the semiconductor industry. Its technology is used in half of all chips and virtually every smartphone, including Apple's iPhone 16, according to reports. Shares have soared 141% since its initial public offering last year.Arm's lucrative business model based on licensing and royalty revenue makes it a solid business. However, while investors might be tempted to buy shares, the ...