Currencies fall

 Sterling hit a 6% fall in two minutes on October 7 (from $1.26 to $1.18).  The Euro faced a very similar jump as well.  This article states that the best explanation would be that the computer programs that automatically generate transactions can have "flash crashes" in the equity markets.  

"Each may have a trigger point which requires the programme to sell an asset (currency, bond or share) when it falls below a certain point, in order to limit losses. These sales drive the price down, which triggers the selling points of other programme and so on. Eventually, the fall is large enough that other elements of the algorithm generate a buy signal. Hence the whole event can be over very quickly."

 

However, there seems to be more problems than just the computer programs because the pound hit a fall when Brexit happened.   The article points out that a decline in the currency is good for exporters and for the "foreign currency earnings of the multinationals listed in the FTSE 100."

"As a trading nation with a current-account deficit, Britain is dependent on the kindness of strangers; the willingness of foreign investors to send capital."

http://www.economist.com/blogs/buttonwood/2016/10/currencies