The Kijun-sen is a key component of the Ichimoku Kinko Hyo trading system, used in technical analysis to identify trends and potential support or resistance levels. It is calculated as the average of the highest high and the lowest low over the last 26 periods, providing a smoothed line that reflects the market's momentum. Traders often use the Kijun-sen in conjunction with other indicators from the Ichimoku system, such as the Tenkan-sen and Senkou Span, to make informed decisions. A price crossing above the Kijun-sen may signal a bullish trend, while a cross below can indicate a bearish trend.