0: Buy 10000 USDC with $10000
1: Deposit 10000 USDC on AAVE
2: Borrow 5000 USDT
3: Sell 5000 USDT for 5000 USDC
4: Wait for USDT to drop to $0.5
5: Buy 5000 USDT with 2500 USDC
6: Repay 5000 USDT and get back 10000 USDC
7: Profit: $2500
If USDC drops (or if USDT rises, for that matter), you might get liquidated.
Note you do get interest on your deposit so that helps offset it a bit.
0: Buy 10000 USDC with $10000
1: Deposit 10000 USDC on AAVE
2: Borrow 5000 USDT
3: Sell 5000 USDT for 5000 USDC
4: Wait for USDT to drop to $0.5
5: Buy 5000 USDT with 2500 USDC
6: Repay 5000 USDT and get back 10000 USDC
7: Profit: $2500