On the difference between Final Price and Relevant Price

Final Price is defined in Article 5 of the 2002 ISDA Equity Derivatives Definitions and is germane therefore to Equity Swap Transactions only and not, say, Forward Transactions (which, circuitously, rely instead on Relevant Price, albeit defined in a similar way).

The Final Price also has separately broken-out scenarios for Basket Transactions (being just the weighted sums of the individual components in the basket). Relevant Price doesn't bother to break these out — whether that is a function of the fact that Share Basket Forwards behave differently to Basket Swaps, or just because the drafting committee was losing the will to live, is a question to which we have yet to get to the bottom.

Don’t hold your breath.