# Relative Strength Index (RSI)

> QuantNexus indicator page for the classic momentum oscillator.

**Route**: `/quantnexus/indicators/rsi/`

## What It Does

RSI measures the balance between recent gains and losses over a configurable lookback window.

## Formula

`RSI = 100 - [100 / (1 + RS)]`, where `RS = average gain / average loss`

## Parameters

- `period` - default `14`
- `movav` - default `SmoothedMovingAverage`
- `upperband` - default `70`
- `lowerband` - default `30`
- `safediv` - default `False`
- `safehigh` - default `100`
- `safelow` - default `50`
- `lookback` - default `1`

## C++23 API

```cpp
#include <nonabt/indicators/rsi.hpp>
auto rsi = std::make_unique<nonabt::RSI>(data().close(), 14, "SmoothedMovingAverage", 70.0, 30.0, "False", 100.0, 50.0, 1);
```

## Common Usage

- Use it to spot overbought and oversold conditions.
- Pair it with trend filters to avoid fighting strong moves.
- Useful as a baseline momentum oscillator in multi-signal systems.