# Average Directional Movement Index (ADX)

> QuantNexus indicator page for the ADX trend-strength measure.

**Route**: `/quantnexus/indicators/adx/`

## What It Does

ADX measures trend strength rather than direction. A rising ADX usually indicates a strengthening trend, while a falling ADX often indicates a weakening or range-bound market.

## Formula

ADX is derived from smoothed positive and negative directional movement values. In practice, it summarizes how directional the recent price action has been.

## Parameters

- `period` - default `14`
- `movav` - default `SmoothedMovingAverage`

## C++23 API

```cpp
#include <nonabt/indicators/adx.hpp>
auto adx = std::make_unique<nonabt::ADX>(data(), 14, "SmoothedMovingAverage");
```

## Common Usage

- Use ADX as a trend filter.
- Combine it with moving average crossovers or breakout logic.
- A common threshold is 20 or 25 for "strong trend" confirmation.

## Practical Pattern

Trade only when ADX is rising and the directional trigger is already confirmed by price structure or another line-based indicator.