Financial trading may be the largest business in the world but it may be also the least understood business in the world. Sudden moves are a mystery to most, arriving when least expected and appearing to have little logic attached to them, frequently doing the exact opposite to a trader's intuitive judgement. Even those who make their living from trading, particularly the brokers and the pundits, who you would expect to have a detailed knowledge of the causes and effects in their chosen field, very often know little about how the markets really work.