# Cross Down (CROSSDOWN)

> QuantNexus indicator page for downward crossover detection.

**Route**: `/quantnexus/indicators/crossdown/`

## What It Does

CROSSDOWN detects a downward crossing event. It is a crossover utility used to trigger bearish or exit logic.

## Formula

`Cross Down = fast line crosses below slow line`

## Parameters

- `period` - default `252`
- `maperiod` - default `2`
- `_movav` - default `SMA`

## C++23 API

```cpp
#include <nonabt/indicators/crossdown.hpp>
auto crossdown = std::make_unique<nonabt::CROSSDOWN>(data().close(), 252, 2, "SMA");
```

## Common Usage

- Use CROSSDOWN for bearish triggers.
- Combine with trend or regime filters.
- Useful as an exit signal helper.

## Practical Pattern

Cross Down often signals loss of upward momentum or confirmation of a trend reversal.