Commercial companies often trade fairly small amounts of currencies compared to those of banks or speculators, and their trades often have little short term impact on market rates.

Since a note has no intrinsic value, there is nothing to stop issuing authorities from printing more of it than they had specie to back it with.

Market strength describes the intensity of market opinion with reference to a price by examining the market positions taken by various market participants. Volume or open interest, are the basic ingredients of this indicator. Their signals are coincident or leading the market.