2015 BBC article. Why market crashes in autumn.

http://www.bbc.co.uk/news/business-30793329

 

2017. Hedge fund telemetry.

Excerpt from BBC article about silver corellation:

When market prices were moving fast, some traders in agricultural commodities such as corn and wheat could find themselves physically unable to get deep enough into the pit to trade.
So they turned to the neighbouring less excitable pit where silver was traded.
The result was that when the price of farm commodities was rising fast in Chicago, silver would tend to go up at in a similar way, through sheer association.
In the 1980s the Board of Trade changed the layout of its trading pits so that silver was no longer adjacent to corn.
But for a long time afterwards, busy farm trading days tended to have a knock on effect on the silver market.
No longer because they were next to each other, but because that’s the way it had happened for decades. There are limits to rationality.