Share your insights or perspective on the financial matter presented in the input.

Trustable, official sources on holdings, purchases and sales by finance academics/professionals?
You won't be able to know the trading activity in a timely, actionable method in most cases. The exception is if the investor (individual, fund, holding company, non-profit foundation, etc) is a large shareholder of a specific company and therefore required to file their intentions to buy or sell with the SEC. The threshold for this is usually if they own 5% or greater of the outstanding shares. You can, however, get a sense of the holdings for some of the entities you mention with some sleuthing. Publicly-Traded Holding Companies Since you mention Warren Buffett, Berkshire Hathaway is an example of this. Publicly traded companies (that are traded on a US-based exchange) have to file numerous reports with the SEC. Of these, you should review their Annual Report and monitor all filings on the SEC's website. Here's the link to the Berkshire Hathaway profile. Private Foundations Harvard and Yale have private, non-profit foundations. The first place to look would be at the Form 990 filings each is required to file with the IRS. Two sources for these filings are GuideStar.org and the FoundationCenter.org. Keep in mind that if the private foundation is a large enough shareholder in a specific company, they, too, will be required to file their intentions to buy or sell shares in that company. Private Individuals Unless the individual publicly releases their current holdings, the only insight you may get is what they say publicly or have to disclose — again, if they are a major shareholder.