Can You Copy Warren Buffett's Portfolio?

The short answer. You can replicate the disclosed US equity positions of almost any famous investor, because 13F filings are public and free. What you cannot replicate is their cost basis, their time horizon, their tax position, the hedges the filing does not show, or their willingness to sit through a 50% fall. Copying the holdings without those is copying the visible tenth of the decision.

What would you actually be copying?

A 13F shows US-listed long positions as at a quarter end, published up to 45 days later. So a copied portfolio is, at best, a portfolio someone else held between six weeks and four and a half months ago, at prices that no longer exist, with any shorts, bonds, foreign holdings and cash stripped out.

For a manager whose edge is patience, that lag is survivable — a position held for eight years does not change much in six weeks. For anyone trading faster, it is fatal.

The four things the filing hides

1. The price they paid. A position that is 20% of a book may have been 5% at purchase and grown there. Buying it at 20% today is a completely different bet.
2. The other side. Options, shorts and non-US holdings are absent or partial. What looks like conviction may be one leg of a hedge.
3. The horizon. A fund with locked-up capital can hold through a decade of being wrong. A private investor with a house deposit in five years cannot.
4. The exit. You will find out they sold in the next filing, up to four and a half months after they did it.

Which companies would you end up owning?

Copying the consensus rather than one manager lands you here, which is worth looking at before deciding it is a strategy:

That is, broadly, the largest companies in the index. There is a version of this observation that is a criticism and a version that is not: professional consensus and the market-cap-weighted index converge because both are dominated by the same few enormous, genuinely dominant businesses.

Is there a sensible way to use this?

Yes, and it is not copying. Use filings as a research funnel: a name several managers you respect have independently bought is a name worth a weekend of reading. Then reach your own view, at today's price, with your own horizon. The filing is where the work starts.

What this cannot tell you

Anything about the investor's actual returns, which cannot be computed from filings without inventing a cost basis.

Educational information, not financial advice. Every figure on this page is read from the source filings when the page loads rather than written into the article, so what you are reading is today's data and not a snapshot of the day it was published.