It has been already "proven" above by others, but ... @officialjustlend

Answer: If you supply 1000 USDD, you can only borrow 850 USDD. This is because of the collateral factor which is not taken into account. The Supply APY is only applied to the net supply of the token amount itself, which is calculated by subtracting the total borrow from the total supply. In this case, it would be 1000 - 850 = 150 USDD. Therefore, the Supply APY of 9.30% would be applied to the 150 USDD. After one year, assuming that the USDD borrow APY and total supply APY have been the same all the time, the profit from supplying USDD would be 150 * 0.0930 = 13.95. The debt from borrowing USDD would be 850 * 0.0517 = 43.945. This would result in an absolute change in USDD balance of 13.95 - 43.945 = -29.995. This would result in a relative change in USDD balance of -29.995/1000 = -2.995%.

Also no, with clarification. If you Supply 1000 USDD, people aren't taking into account collateral factor still. Supply 1000 USDD, you can only borrow .85. So that's 850 USDD. The Supply APY is only applied to the Net Supply OF THE TOKEN AMOUNT itself. So Net Supply (Total Supply - Total Borrow) 1000-850=150 So the Supply APY currently of 9.30% is applied to 150 USDD @TzuhsinChu @mia_wang please check to be sure