Since you are on the topic of expanding the historical data record, I wonder if you could offer some background on the Global Historical Climatology Network (GHCN) and the strange apparent pattern of station distribution in time. (realclimate.org)
(When plotted in raw form, Lauer says the data form a «gigantic cloud» with little apparent pattern.) (sciencemag.org)
In addition to what @George Marian said, a very large portion of trades are from computer programs trained to make trades when certain apparent patterns are observed. (money.stackexchange.com)