There are various ways of spotting the leaders and laggers in the market. You can use highs and lows, for example which index makes a new high before another, or new low before another. This has the advantage of being visual. Or you can use percentage moves, but this takes a lot of calculation and unless you have some impressive system it is harder to measure from highs and lows, although easier to measure by week, month, quarter and year.
With pivots we are considering relative strength and weakness. For example, INDU has made a new all time high on this rally and NDX hasn't yet, but in the last few days especially NDX has led above INDU. Check them out.
INDU held the YP exact, then found support on the Q3P / JulP with 2HP just underneath for a major buy area. It zoomed up to Q3R1, next day jumped above, then rallied to JulR2. It fell back from there, but still holding Q3R1 as support.
NDX (and I am using both cash indexes here to compare apples to apples) broke its YP and actually under all pivots for 3 days, so you wouldn't be thinking first choice to buy unless you used other techniques. INDU beat it to the Q3R1 by 1 day, and NDX had 4 day pause where INDU simply hopped above it. Since then, however, NDX has zoomed all the way above its 2HR1! INDU is nowhere close.
Due to structure of highs and lows last year, INDU will reach its YR1 far before NDX. But for now we can say NDX has resumed market leadership because it reached long term resistance faster than INDU, despite the fact that NDX is below its all time high and INDU is above. This is a bullish development for the markets.