The S&P 500, which has been on a remarkable bull run, might be on the brink of a significant downturn, according to a top strategist. What Happened: Paul Dietrich, the chief investment strategist at B. Riley Wealth Management, has issued a stark warning about the future of the S&P 500. The warning comes in a commentary titled ‘The Stock Market Bubble Is About to Burst — Look Out!’ Dietrich predicts that the index could plummet by as much as 49% when the next recession hits. Dietrich’s warning is based on the current overvaluation of stocks, which he believes is “bizarrely overvalued.” He highl…