The reaffirmation of the Sell rating by Goldman Sachs, despite the increase in price target, suggests that the investment bank sees limited upside or potential downside for Moelis & Co's stock. This could lead to negative sentiment among investors and potentially result in a short-term decline in the stock price. The confidence level is high due to the influence Goldman Sachs' ratings typically have on market perceptions, but not at 100 because market conditions and other factors could mitigate the impact.