like Vanguards/Fidelity...other non-indexed mutuals can hold cash and lots of it, during bear markets I've seen cash go as high as 10%, even higher.
word is most fund managers use spy, qqq, dia as cash substitute when they don't have a specific stock buy, so maybe that day the buying maybe heavy in these, unless they choose to deploy it right back into their stock choice portfolio's.
I really don't like these index calculations that have a divisor - truly a sham. Probably the wilshire is the best because it's merely a total of all the market cap's of all the stocks HQ'd in the USA added together. If the index is 10,000 that means all the stock in the US is valued at 10trillion!.