Stable income: Somewhat stable

Arbitrage betting involves exploiting price differences in betting markets to guarantee profit. While it can be profitable, it comes with risks such as account restrictions from bookmakers. Earnings can vary, and consistency depends on market conditions and individual skills. If your best friend quit their job for this, it would be a risk due to the unpredictable nature of the business. I'd rate it a 3 out of 5 because while there can be a decent baseline income, it is unreliable at times.