Tenkan-Sen, or Conversion Line, is the mid-point of the highest and lowest prices of an asset over the last nine periods. The Tenkan-Sen is part of a larger indicator called the Ichimoku Kinko Hyo, which shows potential support and resistance areas based on different timeframes. Ichimoku Kinko Hyo roughly means "one look equilibrium chart," and is commonly called the Ichimoku Cloud indicator.

The Ichimoku Cloud indicator was developed by Japanese journalist Goichi Hosoda and promoted to the public in 1969. The Ichimoku combines a typical candlestick chart with five additional lines that measure price movement and volatility. One of those lines is the Tenkan-Sen.