While the exact origin of this slang is difficult to pinpoint, it's likely that it emerged from casual speech, gradually shortening the word "finances" over time.
Here's a possible explanation:
* Casual speech: People started using "finances" in a more relaxed way, often referring to it as "my fins" or "your fins."
* Shortening: Over time, this casual usage led to the shortening of "finances" to "fin," becoming a more informal and widely accepted slang term.
It's worth noting that the use of "fin" as slang for money isn't necessarily widespread or universally understood. It's more commonly used in certain regions or social groups.