Reading room · Technical analysis guides · Published 2026-11-10

What the RSI tells you

The Relative Strength Index (RSI) compares recent gains with recent losses on a scale of 0 to 100.

Confirmed facts

• The standard RSI uses 14 periods. Above 70 is called overbought and below 30 oversold, by convention.
• RSI is calculated only from past prices, using Wilder's smoothing.

Historical data

• In a strong, steady uptrend RSI can stay above 70 for a long time without the price falling.

Interpretation

• Treat RSI as a description of recent momentum, not a signal to buy or sell on its own.

Sources

• J. Welles Wilder, New Concepts in Technical Trading Systems (1978)

Educational content, not advice. Disclaimer