Studies · Momentum
Relative Strength Index (RSI)
rsi · Wilder's relative strength index, bounded 0..100
Drawn in its own panelReads one column (close here)Guide lines at 30, 70
Hover the chart to read values · practice data: a seeded random walk with no overnight gaps
What it measures
Compares the size of recent up moves with recent down moves and puts the answer on a 0 to 100 scale. 100 would mean every move in the window was up; 50 means up and down moves were equal. It uses Wilder’s smoothing, so older moves fade out gradually.
How traders use it
- Overbought and oversold: above 70 is read as overbought and below 30 as oversold. In a range these are fade signals; in a strong trend RSI can stay overbought for a long time, so many traders wait for it to come back through the level.
- Divergence: price makes a new high but RSI makes a lower high, a warning that the move is tiring.
- Trend regime: in uptrends RSI tends to hold above 40, in downtrends below 60, which helps read pullbacks.
- Failure swings and the 50 line are used as momentum confirmation.
Parameters
| Name | Value | Default | Allowed | What it does |
|---|---|---|---|---|
| period | 14 | ≥ 1 usual 5–30 | Smoothing length. Wilder used 14; shorter makes it swing to the extremes more often. |