Given a free market price movements reflect changes in supply and demand, and at any one time the price is the balance between the two.
All knowledge and expectations – whether economic, political or psychological – are reflected in the price. The price is therefore the sum of the feelings or opinions of all market participants. As perceptions change, then the price will adjust to reflect this.
A sudden change in fundamentals – the unexpected and presumably the unforeseen – will result in a market shift in perceptions and an abrupt change in price. It can be argued that a Technical Analyst need know nothing of market fundamentals, but we have found that a good balance between the two is the best approach.