Relative Strength, sometimes called comparative Relative Strength, can measure the relationship between two securities, between a security and an index, or between two indexes. This does not refer to the popular indicator called Relative Strength Index. The RSI measures the performance of a security or index against itself by producing a normalized measurement of “up closes” versus “down closes” across a chosen time period. Comparative Relative Strength is used in futures markets in inter-market situations, say comparing European wheat prices to Chicago corn prices as a spread or a ratio. We also see intra-market calendar spreads, another form of measuring…