The golden cross is a technical indicator that occurs when a stock's 50-day moving average crosses above its 200-day moving average. This is generally considered a bullish signal, as it suggests that the stock's short-term momentum is increasing relative to its long-term momentum. In the case of UDR, the formation of a golden cross could indicate a positive trend for the stock in the short term. However, it's important to note that seasoned investors don't blindly trade golden crosses and consider other factors like price levels and company fundamentals.