Shares of chip designer Arm Holdings surged 25% above their initial public offering price of $51 in the company’s stock market debut today. A lot went into deciding on that price. Today, we dig into what it takes to make an IPO “pop.” Later, the United Auto Workers plans to target its work stoppages as a strike looms. And will Social Security’s cost-of-living increase be enough to help older Americans keep up with inflation next year?