The Trading Wallet shows you the $USD you have available to trade, your open obligations and your trading history.
Total Cash Value - The current amount of $USD held in your Trading Wallet.
Open Commitments - Each open order or bid must be “covered” by an equal value of USD from your total cash value. The amount equal to your open buy orders is “held” to cover to cost of your bids.
Buying Power - This is your Total Cash Value ($USD) less your Open Commitments. If you want more buying power you will need to deposit $USD into your Trading Wallet or reduce your open commitments.