Down Day (DOWNDAY)

QuantNexus indicator page for DOWNDAY.

Route: /quantnexus/indicators/downday/

What It Does

DOWNDAY measures whether the current bar closed lower than the prior bar. It is a simple directional utility indicator.

Formula

Down Day = 1 when Close < Previous Close, otherwise 0

Parameters

• period - default 14

C++23 API

#include <nonabt/indicators/downday.hpp>
auto downday = std::make_unique<nonabt::DOWNDAY>(data(), 14);

Common Usage

• Use DOWNDAY for direction counting.
• Combine it with rolling windows.
• Useful as a Boolean input to custom logic.

Practical Pattern

A high count of down days can indicate persistent selling pressure.