Frequently Asked Questions
Sources for institutional ownership data can be found on Bloomberg, if one happens to pay the $20k a year that a Bloomberg system costs, or on WONDA, if one can afford the $25k a year that costs, but a cheaper source can be found on yahoo.finance. If you search on a stock symbol on the Yahoo.finance home page along the right there is a menu that includes OWNERSHIP down at the bottom. I did it for LNKD in here: http://finance.yahoo.com/q?s=lnkd&ql=1
Bloomberg, however, provides the most comprehensive and up-to-date information.