Three cost views
Tax lots are the official lot-level record used for tax reporting and realized gain/loss matching. Average cost is a quick position display metric. Diluted cost is an analytics metric that can include realized P&L, option premium and strategy income to estimate a practical break-even level.
Why diluted cost matters
For covered calls, cash-secured puts and Wheel strategies, premium income can change how you think about the remaining stock position. Diluted cost helps answer: after realized income from this symbol, where is my effective break-even?
Diluted cost is not tax advice and should not replace IBKR tax lots or official statements for filing.
How IB Dashboard helps
IB Dashboard parses IBKR XML/Flex Query exports to connect trades, positions, premiums, dividends, fees and realized P&L, then shows tax-lot style cost, moving weighted cost, diluted cost, sell analysis and Wheel tracking.