With your $500 bonus, you have several options available to you. You can invest it on the Gate.io platform, by going to the Earn tab, selecting HODL & Earn, and then Flexible Term and Flexible Staking to find USDTEST. Alternatively, you can also do this on the app by going to the Markets tab, selecting HODL & Earn, then Flexible Term and selecting USDTEST. Investing your bonus in USDTEST is a great way to make the most of your bonus and start earning returns on your investment.