&quot;Efficient&quot; has a very specific meaning in this case.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Efficient-market_hypothesis" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Efficient-market_hypothesis</a>