13F filings don&#x27;t show any short positions or any private positions.<p>I&quot;m guessing this is mostly what leads to this discrepancy.  It&#x27;s also a reason why the industry really hates 13F filings.  They don&#x27;t tell the whole story.<p>A fund could show they are long $1,000,000,000 of Microsoft but have in the money puts for the same delta value making them effectively flat Microsoft in the real world.  But according to the 13F filing they are long.<p>Infact this is often one of the first mistakes people make when joining the industry.  They see the 13F and figure that they now know what positions a hedge fund has, when in reality its more akin to saying you&#x27;ve see Facebook&#x27;s source code by selecting show code from your web browser.<p>Those two things are related but very far apart.