Relative Strength Index (RSI)
Also called: RSI, relative strength index
RSI measures the size of recent gains against recent losses on a 0–100 scale, conventionally flagging above 70 as overbought and below 30 as oversold. Its most common misuse is treating those thresholds as trade signals: in a strong trend RSI can sit above 70 for weeks while price keeps rising. Practitioners lean more on divergence between RSI and price than on the levels themselves.