The concept of Total Return Index Value (TRIV) is similar to that of Stock Price Index Value (SPIV), with the key difference being that TRIV takes into account both the aggregate market value of the index constituents (SPIV) and their paid dividends/distributions. This calculation is done at the end of the trading session for all S&P/TSX indices. TRIV is a crucial metric for investors as it provides a more comprehensive understanding of the overall performance of an index.