VTSAX Sep-18    29.68   1.29   4.54%

vtsax is one of the vanguard total market index funds, and uses an unbiased capitalization weighted index to track the performance of the entire u.s. stock market.

this index rose today by an amount that corresponds to an increase in stock prices across the board, and is not affected by changes in the membership of specific sub-indices.

what you should really be complaining about is the absurdity of reporting absolute point variations in daily dow (or s&p500 or nasdaq or wilshire 5000) movements rather than using percentage variations.

a 400 point movement in the dow in 1970 was a big deal. it is significantly less so today since the value of index itself has increased in the last 40 years. at constant daily volatility, larger movements are more common today than in the past, and not worthy of gaga excitement.

this cuts both ways. the doomsayers bemoaning a 400 point single-day drop are just as idiotic as the rah-rah boosters rejoicing over a 400 point single-day increase. with the stock-market long-term trends are what matter for sensible (i.e. buy-and-hold) investors. speculators, on the other hand, deserve whatever shit comes their way.

now go back and compute the % change in dow for today, and see how closely it matches that of vtsax (they should be reasonably close if the change in the dow accurately reflects the broad market movement, and should be significantly different if the %change in the dow was due to some cherry-picking shenanigans).

according to yahoo, the sep-18 dow change was around +3.9%. the sep-18 change for mid-cap and small-cap stocks was anywhere from +6% to +7.2% (depending on the capitalization buckets of the sub-indices). the change in the dow is thus entirely consistent with its large-cap bias.