that is a 2.39% return and it does not include other fees such as sending fee (wire transfer fee $40) and reeving fee ($15) and buying fee (commission rate).
Edit:
Example 1: let's say you place $100/BTC order and Bitcoin price goes below $1. You will receive 1 Bitcoin.
Example 2: if Bitcoin prices goes above $100 then you will receive certain percentage on price increase and not full profit. So it is best to invest it yourself.
The 2.39% is the actual return, the OP annualized this rate to assume you would continue to get this rate over a year. Regardless this is likely not a legit investment opportunity (even if you ignore the costs involved). The return is simply too high