Western color psychology.

Red is considered a very lucky color in China.

And I guess this is why red is positive (is green negative?) in much of East Asia in finance.

Hence the emoji for chart increasing being mostly drawn as a red line

https://emojipedia.org/chart-increasing/

> (is green negative?)

From the link at your link, yes, negative is green in Japan.

https://blog.emojipedia.org/why-does-the-chart-increasing-em...