For those who really want to dig in on this issue, the referenced paper is &quot;The 8-K Trading Gap&quot; [0]. From the abstract:<p><i>When a significant event occurs at a publicly traded company, federal law requires the firm to disclose this information to investors in a securities filing known as a Form 8-K. But the firm need not disclose immediately; instead, SEC rules give companies four business days after the event occurs within which to file an 8-K. These rules thus create a period during which market-moving information is known by those inside the firm but not most public-company investors — a period we call the “8-K trading gap.” In this Article, we study how corporate insiders trade their company’s stock during the 8-K trading gap.</i><p>TL;DR: as anyone would expect, this is another way that executives make lots of money. In this case, 35 basis points over a period of less than four days.<p>I wonder whether it&#x27;s significant that this work was done by law professors rather than by economists or B-school profs?<p>[0] <a href="http:&#x2F;&#x2F;papers.ssrn.com&#x2F;sol3&#x2F;papers.cfm?abstract_id=2657877" rel="nofollow">http:&#x2F;&#x2F;papers.ssrn.com&#x2F;sol3&#x2F;papers.cfm?abstract_id=2657877</a>