What is available funds?

Available funds, as its name implies, represents money that is readily accessible and can be used immediately by the account holder. Customers are free to spend these funds as they please.

What are available for trading values?

The Available for Trading values show you the state of your account at a glance. Your Available Funds tells you if you can put on a trade. Your Excess Liquidity tells you whether you have sufficient cushion to maintain your current positions, your Buying Power tells you how much you have at your disposal including your equity and IBKR's margin.

What is the difference between available funding for trading and option buying power?

In the example below, the account has $313.66 in Available Funding for Trading and $113.80 in Option Buying Power. The difference of $199.86 is the monthly accrued margin interest, which is debited from the cash balance on the 2nd to last business day of every month.