I did a bit of online arbitrage (buy/sell) by myself and made around 2400$ in 2 months (maybe 5 hours/week) and I had written about this as an intellectual vitality essay, but I think this would really strengthen my ECs if it was considered one.
My current EC repertoire looks like
Chess - 2012 Unanimous U20 National Chess Champion, Multiple Provincial and Municipal titles, Provincial Ambassador, Tutor etc.
Violin (1st violin for ensemble)
Piano (Lol yes I'm Asian-American)
Basketball (outside of school)
VP of Finance/Treasurer for a company
McDonald's employee (lol dont be jelly)
If I were to use arbitrage as an EC, which one of the ECs above seems the most fittable to replace?