Fast Up Button on Discord

What it signals here

server usage

Used in announcement channels to flag rapidly growing servers or events.

reaction use

Reaction on messages about wins, boosts, or improvements in server metrics.

emote mapping

Closest custom emote analogs are :rocket: or :chart_with_upwards_trend: in many servers.

gaming context

Used to celebrate a player ranking up fast or a team's win streak accelerating.

role meaning

In role-assignment servers, sometimes used as a symbol for 'fast track' or advanced members.

See it elsewhere