The downgrade from Overweight to Equal-Weight by a major analyst like Wells Fargo could lead to a neutral short-term impact on MMC's stock price. The setting of a price target at $212 suggests that Wells Fargo sees limited upside potential from the current levels, which might influence investor sentiment. However, the impact is considered neutral because the downgrade is not to Underweight, indicating that the stock is not expected to perform poorly, but rather to align more closely with the market.