What's a NASDAQ, daddy?

There are many out there, I would assume, who would be glad to explain to me the terminology and psychology of Wall Street. (For those of you who came in late, "Wall Street" is a general term for all those players, large or small, who accumulate wealth that isn't really there based on promissory notes known as "stocks" or "bonds.) Depending on how many of these are bought or sold, and for how much, the boys and girls playing on Wall Street look to a mysterious number from a mysterious source, called the Dow-Jones average, to measure the economic health of America and beyond. No, I don't know who Dow or Jones are, and why anyone would care about this number they come up with.
But I am more fascinated by the psychology of this group of men and women who, I assume, have some intelligence and self-awareness. But reports of Wall Street reflect either a high-anxiety group which spooks at the slightest shift of the wind, or a group living in its own little world where, when the economy improves for everyone else, they act as though the sky were falling.
This sort of behavior reminds me of a librarian I used to know. She would keep a rigid record of how many books had been borrowed from that library, inasmuch as that is the way libraries measure their productivity. At the same time, she begrudged every book that went out, as though each one were her personal treasure and she suspected the book would not be returned in time or in good shape.
So what I'm suggesting here- and those of you who know anything about this, please let me know- is that these stockbrokers just hate to see others doing well. See, they think there's only a finite amount of money, and when others get their hands on some of it, there's less for them. So when the fecal matter hits the cooling device, stocks go up.
But I'm probably wrong. I hope I am.
ADDENDUM: No, no one has yet told me how full of it I was, although not all the votes have been counted yet.. But I did get one fascinating insight: we are talking here about financial people, bean-counters. bottom-line types. As such, they have two major obsessions: numbers and change. Nothing will scare 'em more than any sort of serious alteration in the status quo. ("Serious" being a subjective but important word.) If that mystical number that Dow-Jones or any other self-appointed guardian at the gates comes up with is too high or too low, chaos ensues.
Because that means serious change is necessary, something between throwing everything out and starting from scratch, versus merely rearranging the deck furniture on the Titanic. And when faced with something in-between, they freeze up. Two must two must equal four, or we are all doomed! No, twenty-two is not an option.