A 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 Entegris, the formation of a golden cross could indicate a positive trend for the stock in the short term. However, it is important to note that seasoned investors do not blindly trade golden crosses, but use them as a signal to start looking for long positions based on other factors, such as price levels and company fundamentals.