Ownership > 100%
List of possible reasons behind the infrequent cases where we have total institutional ownership that exceeds 100% of the common shares outstanding for a specific company:
Double-counting
- On the 13-F filing, each institutional holder must report all securities over which they exercise sole or shared investment discretion. In cases where investment discretion is shared by more than one institution, care is generally taken to prevent double-counting, but there is always the exception. Another cause of double-counting is a company name change for the 13F filer where the holdings are accounted for under both filer names.
Short Interest
- A large short interest amount affects the institutional ownership amount considerably because all shares that have been sold short appear as holdings in two separate portfolios. One institution has lent its shares to a short seller, while the same shares have been purchased by another reporting institution. Consequently, the institutional ownership percentage reflected in the 13-F filings is overstated as a percentage of total shares outstanding.
A gap between 'as of' dates
- In the case where gaps between the 'as of' dates of the holdings and the shares outstanding arise, the percentage owned could be skewed due to a sharp increase/decrease in shares out. Again, this case doesn’t come up very often but the results are unavoidable.
Other possible reasons:
a) An overlap occurs amongst reporting institutions;
b) The 13F filing includes holdings other than common stock issues;
c) Mutual fund money is co-advised and incorrectly reported by multiple institutions.