The red–green mapping for up and down reverses by market

What it is

A Shanghai trader reads a green candle as a fall; a New York trader reads the same green as a rise. East Asian exchanges paint red for up, green for down; US and European boards paint the reverse. Neither set of eyes is sharper. The venue wrote gain and loss into opposite colours. A global quote page with one mapping will invert P&L for half its users.

Why it happens

Up/down colour is a venue convention, trained daily by boards, newspapers and TV tickers. In Chinese usage red also stacks with joy, positive, profit; green with loss and “leaving”. In English, green stacks with go / growth, red with stop / loss. The associations point opposite ways, so the same candle fires opposite classifications in the two markets.

This is not traffic lights, and it is not the same table as error / success. Painting a fall in “error red” on a red-up market makes losses look festive and gains look like failure. Signs (+/−) and arrows can share the load, but traders scanning a board eat colour first; if colour is reversed, the glyph is too late.

Studying it

Classification: briefly show a red or green candle or coloured numeral with no digits, and ask up or down. Independent variables: the observer’s primary trading venue, whether an arrow or sign is also present, professional trader or not. Dependent variables: accuracy, latency, direction of errors relative to the venue convention.

Contrast markets, not languages. Two cities that share a language (different boards in Singapore, for example) may still differ; the independent variable is the market, not the UI language.

Where it stops holding

• Crypto and CFD platforms often follow the dollar board (green up) even when users sit in East Asia; those users may already have trained a second convention. Do not recolour by passport. Follow the market the product tracks, and allow a personal toggle.
• Colour-vision-deficient users cannot rely on this pair; a correct convention still needs arrows or signs.
• One-off marketing figures (“today’s volume”) are not up/down. Painting them red/green invents a ticker reading that was not there.

Applying it

• Red/green on quotes, positions and P&L follows the target venue’s board, not headquarters habit.
• Ship a “red-up / green-up” toggle, default to the market, remember it on the account — do not re-guess from system language every session.
• Always pair direction with a sign or arrow; colour accelerates, it is not the only code.
• How to check: with traders from the target market, hide the digits, leave the colour, ask whether the candle is up or down. If they answer the opposite way, you are still on the other board.

Related

• Same group: F5.10.2 Funeral and celebration colours differ by culture · F5.10.3 Cross-market products need a configurable semantic colour map
• Nearby: F5.02 Semantic colour · J2.03 Information does not rely on colour alone
• Search terms: price color convention · candlestick colours · red up green down