How the numbers are built

Ten Year Hold replays real companies over real decades. The numbers are our best effort from public filings, not a price feed. They are good enough for a game and will have errors, some we know about and some we don't. Treat every figure as an estimate.

Ten Year Hold is a game about market history, for entertainment and education. No real money is involved. Results are historical, not a forecast or backtest, and nothing here is investment advice. Past performance does not predict future results.

The game

• Each daily shows a start year and six sectors, drawn at random. One daily for everyone, turning over at midnight New York time.
• The candidates are the five largest companies in each sector by market value at the start of that year, drawn from that year's membership of a widely followed large-company benchmark, including companies later delisted.
• Sectors come from the industry codes in each company's SEC filings of the period, mapped to twelve broad sectors, with corrections where a code misleads.
• You hold one pick per sector, equal weight, $1,666.67 each of a notional $10,000, for ten years with no rebalancing. No real money is involved.
• The grid is 121 points: the start of the year, then 120 month-ends. Start year 2000 begins at 2000-01-31.
• The margin is your ten-year total return in percent minus the market's, in percentage points, to one decimal. A pick "beats the market" if its ten-year value finishes above the market's.
• Draws where under 10% of the possible portfolios beat the market are skipped from the daily schedule. They stay in practice. That filter leans against the strongest later markets, and looks at no other outcome.

Prices

• Prices are implied by fund holdings in SEC filings: the shares and market value a fund reports for a holding divide to a price. Where no fund filing covers a company, an adviser's 13F holdings report can supply it instead.
• A month is observed when a filing prints a price for it. Filings don't cover every month. Holes up to a quarter are interpolated, and a price is held flat under two quarters.

Dividends

• Dividends are reinvested at the month's price.
• In order of preference, a figure is one printed in two filings, one printed once, or one derived or carried forward from other filings.
• Most payment dates are computed quarter ends, not actual dates, and most quarterly amounts are an annual figure divided by four.

What happens to a company that leaves

• Cash deals: the proceeds go into the market from that month.
• Stock deals: the holding follows the acquirer.
• Bankruptcy: the last price holds until the shares are cancelled, then zero.
• Spin-offs: folded into the parent's value.
• Delisting with no known terms: the last price goes into the market.

The market

"The market" is a broad US total-return equity fund proxy: that fund's holdings, valued at the same implied prices, plus the fund's income. We have no connection with any fund, index or company in the game, and none of them has endorsed it.

Where the numbers are weakest

• A year at a seam between two filings can count a quarter's dividend twice, or drop one.
• Foreign filers' years are the weakest.

Spotted something wrong? Write to hello@tenyearhold.com.

What the game shows

For each company the game shows one number, its ten-year multiple, plus what became of it. For the portfolio and the market it shows the monthly line. Titles and badges describe what happened to a past pick; the definitions are one tap away. Event markers, such as a bear market, use month-end values. Your percentile compares your result with everyone else's first play of that day's daily, one per device. Recaps open after a daily's day has ended.

These are calculated results for a game. Nobody earned them, and they can't be repeated as an investment.