Every line, every percentage and every bar on this page is relative to SPY: a factor’s growth over the window divided by SPY’s over the same window, so 0% means it tracked the index and the line above or below zero is the out- or under-performance. It is a ratio of growth rather than a difference of two returns — over ten years those are not the same number, and only the ratio is what you would have earned holding the factor against the index. Z-Score standardizes each factor’s latest session against its own trailing 252-session distribution of daily relative moves, so it says whether today was unusual for that factor — the same −0.4% is an ordinary day for a small-cap fund and a notable one for a low-volatility fund. Tick a row, or a group’s All / None, to change what the chart draws — the page opens on the six Style factors because twenty overlapping lines cannot be read. This describes relative performance that has already happened — it is not a forecast.