Investor Track Records: How Little Is Actually Public

Berkshire Hathaway's share price rose 19.7% a year from 1965 to 2025. The S&P 500 with dividends included rose 10.5% a year. Both figures come from the table in Berkshire's own annual letter, dated 28 February 2026.

This guide reads two investor records that can be checked against a primary document, Berkshire's and a Fidelity mutual fund's, including the years each fell behind the market. It then explains why the return figures quoted for well-known hedge funds cannot be checked against a filing.

A public record is a return series that the fund or company publishes itself, in a document anyone can open. This guide uses two kinds.

A company such as Berkshire Hathaway reports to its shareholders in an annual letter. A registered mutual fund files shareholder reports with the US Securities and Exchange Commission (SEC) under the Investment Company Act of 1940. EDGAR is the SEC's online filing database, where those reports are published.

Both kinds give a series that can be set beside an index. Neither shows whether skill or luck produced the result.

Berkshire's letter carries a table called Berkshire's Performance vs. the S&P 500. It gives the yearly change in the market value of one Berkshire share. Beside it sits the yearly change in the S&P 500 with dividends included, which means the index return counts the dividends its companies paid.

We use the table in the letter dated 28 February 2026. The 2024 letter gives the same figures for 1965 to 2024.

The Berkshire column is the market price of one share. It shows the change in the market price of the share, not the company's accounting profit. The gap in a year is Berkshire's figure minus the index figure, in percentage points. A percentage point is one unit of a percentage: 10% against 8% is a gap of 2 points.

Three early periods are not calendar years. The 1965 and 1966 figures are for years ending 30 September. The 1967 figure covers 15 months.

Berkshire was ahead of the index in 40 of the 61 years and behind in 21. The three largest misses came in 1999, 1975 and 2009. In 1999 Berkshire's share price fell 19.9% while the S&P 500 rose 21.0%, a gap of 40.9 points.

In 1975 the gap was 34.7 points. In 2009 it was 23.8 points.

The share price also fell further than the index in some bad years. In 1974 it fell 48.7%, against 26.4% for the index.

Single years are noisy. Runs of years smooth that out.

The runs below are the stretches where Berkshire lagged. We picked them to show that the verdict depends on the period. Berkshire trailed the index in 2003, 2004 and 2005. Over those three years the share price rose 21.7% in total, against 49.7% for the S&P 500.

It trailed again in 2019 and 2020, with totals of 13.7% against 55.7%. Over the seven years from 2019 to 2025, the share price compounded at 13.8% a year, against 17.3% for the index.

The chart splits the record into six fixed periods. Berkshire led the index in the first five. In the last period, 2015 to 2025, it compounded at 11.6% a year against 13.5%. We compounded the table's yearly figures ourselves, so they can differ from the letter's own totals by about a tenth of a percentage point.

The choice of period changes the verdict.

The 20 years from 2006 to 2025 favour Berkshire, at 11.3% a year against 11.0%. The 17 years from 2009 to 2025 do not, at 12.9% against 14.8%. We picked those two periods to show the problem. The six periods in the chart are fixed.

Peter Lynch's Magellan record is public because Magellan is a registered mutual fund. Fidelity's own fact sheet lists Lynch as its manager from 1977 to 1990. A 1994 Magellan filing states that he retired from Fidelity's management company on 31 May 1990.

EDGAR's list of Magellan filings begins on 31 January 1994. The report we used is the annual report for the year ended 31 March 1995, filed on 8 May 1995. Its ten-year table starts on 31 March 1985, so it covers the last five years of Lynch's tenure. The years from 1977 to 1985 are not in it.

The report states returns with dividends and capital gains reinvested. Magellan's figures leave out its 3% sales charge. The index figures carry no costs at all.

Over the 10 years to 31 March 1995 the fund compounded at 17.59% a year, against 14.45% for the S&P 500. Over the last year of that table it returned 8.21%, against 15.57%.

That window opens in 1985, so about half of it falls after Lynch left in May 1990. It is Magellan's record, not his.

The chart uses the report's monthly values to work out each calendar year from 1986 to 1994. The monthly values are the report's own. The yearly figures are our arithmetic. Magellan was ahead of the index in five of the nine years and behind in four.

It trailed in 1987, with 1.0% against 5.3%. In October 1987 alone, Magellan's value fell 25.8% and the index fell 21.5%.

It trailed again in 1990, the year Lynch retired. It also trailed in 1992 and 1994. In the same report, an interview with Jeff Vinik, the fund's manager in 1995, says Magellan has historically lagged the market in corrections. Lynch had retired five years earlier.

The SEC's investor site describes a hedge fund as a private, unregistered investment fund. It says hedge funds are not marketed to retail investors. It also says they are not subject to the disclosure requirements that apply to mutual funds. Claims made by a hedge fund can be hard to verify, the site adds.

Four such names are Tudor (run by Tudor Investment Corporation), Quantum (Soros Fund Management), Pure Alpha (Bridgewater Associates) and Medallion (Renaissance Technologies).

Return figures for these funds circulate in print and online. None is published in a filing that we have opened, so this guide quotes none. A mutual fund's record is a filing. A hedge fund's record has no such guarantee.

Two records are a small sample. We chose them because they are public, not because they are typical. Both also still exist.

A fund that closes leaves no such record. Most funds do close. Our guide to why the S&P 500 is hard to beat follows what happens to a starting group of funds over 20 years.

A record shows what happened. It does not show whether skill or luck produced it, or whether the result will repeat. Both records here include years behind the index, which a single headline figure hides.

The two records here show years behind the index as well as years ahead. For the funds with no filing, there is no primary document to check against. Our guide to what a hedge fund is covers how these funds are structured.

This explainer is part of the YX Insights Academy. Each one takes a single idea and checks it against real data.

The same approach runs through everything else we publish:

Good places to start on the website:

Berkshire's share price compounded at 19.7% a year from 1965 to 2025, against 10.5% for the S&P 500 with dividends. It was ahead in 40 of the 61 years and behind in 21. Over 2019 to 2025 it compounded at 13.8% a year against 17.3%, by our arithmetic from the same table.

Fidelity Magellan's shareholder reports are filed with the SEC. Its EDGAR list starts on 31 January 1994. The annual report for the year ended 31 March 1995 has monthly values from March 1985, which covers Lynch's last five years as manager. The earlier years are not in that report.

Hedge funds are private, unregistered funds. The SEC's investor site says they are not subject to the disclosure rules that apply to mutual funds. No filing guarantees a published return series, so this guide quotes no return for any hedge fund.

A track record shows what a portfolio returned. It does not show whether skill or luck produced the result. Berkshire's table, for example, has 21 years behind the index alongside 40 ahead. The choice of period can change the verdict.

DISCLAIMER: This article is strictly educational. Any information or analysis in this note is not an offer to sell or the solicitation of an offer to buy any securities. Nothing in this note is intended to be investment advice and nor should it be relied upon to make investment decisions. Any opinions, analyses, or probabilities expressed in this note are those of the author as of the note's date of publication and are subject to change without notice.