There's no mythical "they" that's any more "wired" to news than any other market participant. It would be folly to think that the Labor Dept. calls up Dr. X. 15 seconds before unemployment so he can trade 5000 ES in front of the number. If Greenapan died on the street it's virtually random which broadcaster or News service would be first to air the report. Possibly some astute passer by would whip out his cell phone and hit every bid in the spoo's for the first ten handles before calling for a paramedic. I had a particularly great trade when flight 587 crashed in Queens a couple of months after 9/11. I happened to be watching CNN which I never have on during the open. They broke to a large black cloud of smoke near JFK that I recognized could only have come from a large plane crash. I sold NQ and took out about 30pts in several minutes. As I surfed around on cable the networks didn't pick up the crash for 5-10 minutes. If I'd been watching CNBC I wouldn't have had a clue as to why the market was in, no pun intended, a death spiral. I was just lucky. Generally for "scheduled" reports and news Reuters is the standard. Walk onto any Exchange floor or institutional trading room and that's where the news will break. Of course now with several national cable news stations and network affiliates all over the country, a sudden story, i.e. death, terror, could originate from most any where. But there is no ordained few that are privy just because of who they are. If you remember millions of Americans already knew about the events of 9/11 before the President was summoned from that school room in Florida.
This is an astute observation. The phenomenon you are describing is called "ringing" in the Physical sciences. It is definetly _THE_ most blatant display there is that the markets act as some kind of damped harmonic oscillator. There are strategies that deal with these phenomenon. I leave it as an exercise... nitro