LEARN THE DESK / INDICATORS
Technical indicators explained: RSI and Bollinger bands
Compare momentum, trend and price dispersion. Calculate RSI and Bollinger bands from your own closing prices.
Indicators answer different questions
A moving average smooths prices to show direction. RSI compares gains with losses to describe momentum. Bollinger bands show how spread out recent closing prices are. A price outside a band is unusual relative to that window, but is not automatically a reversal signal. RSI divergence means price and RSI make different highs or lows; this observation needs context and is not a guaranteed turning point.
Try it with your own numbers
Local calculation only. These inputs are illustrative, not live quotes. Nothing you enter is uploaded.
Worked example
If the average gain is $2 and the average loss is $1, the gain/loss ratio is 2 and RSI is about 66.7. This is not a 66.7% chance of an upward move.
The calculation
RSI = 100 − 100 / (1 + average gain / average loss). Bands = mean20(close) ± 2 × population SD20(close).Method and references
Arithmetic is shown above so you can reproduce the result. Indicator background: J. Welles Wilder, New Concepts in Technical Trading Systems (1978); John Bollinger, Bollinger on Bollinger Bands (2001). These references explain methods, not a claim that TickSPY predicts prices.
Exercises use the values you enter, not a hidden market feed. Examples demonstrate mechanics; they are not evidence of profitability. Reviewed October 11, 2026.
What this cannot tell you
The exercise seeds 14-period RSI from the first 14 changes and then uses Wilder smoothing. Bands use the latest 20 closes. The desk’s indicator score is a summary of readings, not a forecast.