RSI is basically the indicator that tells us the momentum or strength of a market movement. Below is a formula for calculating RSI. Such an indicator indicator Otherwise, all calculations will be made by the graph program automatically. RS = average number of days close "with profit / average number of days close" with loss. RSI has a reading of 0 - 100. A trend is always considered "overbought" by traders when the RSI reads upwards 70, and "oversold" when RSI shows 30 down. Since RSI is a lagging indicator, it also has a weakness alone. The strong and strong market movements can have a strong impact on RSI and it may give a "false" signal.