These via the WSJ round-up
(bolding mine)
- "I initially doubted what I saw on my screen," said Kenji Yoshii, a foreign exchange strategist at Mizuho Securities
- Traders and strategists said the initial catalyst for the pound's drop came from remarks by French President François Hollande ... His comments came early in the Asian session, where light trading volumes likely exacerbated the move, they added
- "There was a complete lack of two way interest in buying the pound on the way down," said Jeffrey Halley, a senior market strategist at Oanda.
- Chris Weston, chief market strategist at IG, a broker. "This is the sort of time when the big U.S. traders are going home and Asian traders are getting back to the desk"
The most likely cause of the pound's sudden drop on Friday was a so-called 'fat finger' trade-that is, an error by a trader-or a rogue algorithm, said Bart Wakabayashi, managing director and head of Hong Kong foreign exchange sales at State Street Global Markets.
"When you have that big a move you're triggering a lot of things on the way down, like stop losses and options barriers, which exacerbate the whole move"
