The three leading ETFs for the S&P 500 along with their expense ratios are: IVV , expense ratio 4 basis points; VOO , expense ratio 5 basis points; and SPY , expense ratio 9.5 basis points. First, you would have to be nuts to purchase one of those when you could purchase IVV, VOO or SPY with costs approaching zero. In all the computer made over 30 million random selections of individual annual returns and inflation levels for portfolio assets to assemble the probabilities in the table in Figure 5.