Everyone knows that the markets; the stock market, the bond market, currency markets, etc. are defined by ups and downs.
Nowhere else does a simple up or down arrow; a plain green or a red icon, have so much immediate force and presence in the human mind. It’s as if the entire world senses and perceives that tiny red down arrow, as a sign of impending doom, or as the very bringer of apocalypse (“the end of the world as we know it”).