All trades are sent to the Ethereum blockchain for settlement. The most common reason why these transactions fail:

1) Adjusting the gas limit lower will likely cause your transaction to fail due to an "out of gas" error.

2) The expected price of the trade fluctuated outside the allowed threshold of slippage tolerance. If your requested trade suddenly changed in price beyond the allowed amount of slippage (default is 0.5%), then the transaction will fail. This occurs in order to protect you from losing more funds because the price changed significantly during your trade request.

​For these reasons, we highly recommend that you do not manually adjust the transaction's gas settings post-trade confirmation.