This is a sudden difference from the previous quotations. We can say that this is the moment hard "collision" of buyers and sellers, "bull" (see) and "bears" (see). A spike always characterises market nervousness. Unlike a fracture, a gap (see), there is no spike during break time. It usually appears after the release of critical market news, the price change can be quite unexpected. This is why we recommend checking our calendar of economic events as often as possible before making a deal.