Effectually and Efficiency

adverb

• In an effectual manner.
  • usage: "Bismarck was constantly criticised by the more liberal newspapers, and he retaliated by passing an emergency decree that effectually muzzled the press"

• (adv.) With effect; efficaciously.
• (adv.) Actually; in effect.

noun

• The ratio of the output to the input of any system.
• Skillfulness in avoiding wasted time and effort.
  • usage: "she did the work with great efficiency"

• (n.) The quality of being efficient or producing an effect or effects; efficient power; effectual agency.
• (n.) The ratio of useful work to energy expended.

Efficiency is the degree and speed with which a market accurately incorporates information into prices.