The same grid for every stock in the weekly 500-stock universe during the period shown (point-in-time membership). Weeks a stock was outside the universe are dimmed; weeks it was in the top-15 portfolio have the bold border.
Each cell is the stock's return from one Friday's close to the next. Bold purple border = in the top-15 portfolio that week. Dimmed = not in that week's 500-stock list (the return is still shown). Dots = its rank when the week began, more dots = better: ●●●●● rank 1–20, ●●●● 21–40, ●●● 41–60, ●● 61–80, ● 81–100, none beyond 100. Blank = not trading. The tooltip gives the exact rank. "Period" compounds every week shown, in the universe or not. "Universe avg" is the equal-weight average return of that week's universe stocks, a benchmark for the portfolio row. Click a stock's name for its chart (the screener's stock view, in one reused tab; grey names have left the universe and have none). Click a week's date to sort by that week's return (click again to reverse). With an industry chosen, the extra footer row averages the stocks shown that were in that week's universe. Before costs and tax.