[speedplane]

> There are literally savings accounts with interest rate over my mortgage interest, meaning there is a zero risk arbitrage opportunity.

Many utilities give an 8-9% interest rate on bonds, with very little risk (Comcast isn't going bankrupt soon). That said, there's no such thing as zero-risk arbitrage.

[alkonaut]

When the savings are state guaranteed in the savings account, the risk is basically limited by the credit rating of the nation. It’s never zero but for stable economies it’s as low as you get