Anxiety has given way to hope on Wall Street. Stocks are back near records, recovering from a slump spurred by fears that the excitement about the artificial-intelligence boom has outstripped the potential profits.Optimism about AI has proved durable. But other important factors are also powering gains. Here’s a look at some of the reasons investors expect that the rally could go further from here: Stock valuations could be worseStocks currently look very expensive by some measures, such as traditional pric ...