One year's profit that is expected to be earned by managing the your deposited crypto assets with this service.
The annual interest rate is the figure that would be obtained if the profits earned from the start of trading with this service to the present were earned for one year at the same pace.
For example, if 1,000,000 yen turns into 1,050,000 yen in the first month after you start trading this service, your assets have increased by 5% in that one month.
If you continue to make profits for one year at the same pace, your annual interest rate will be 60%, since 5(%/month) x 12(months) = 60(%).