erstwhile gameA little hindsight.
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A little hindsight.

Erstwhile Game is an independent browser puzzle about investing through a piece of history. Start with $10,000, spread ten chips across seven options, and see what happens over five years. You can hold or rebuild your portfolio at years 2 and 4.

This site has its own interface, implementation, clue wording and puzzle schedule. It is independently operated and is not affiliated with or endorsed by any other game of a similar name.

The two ways to play

Daily gives everyone the same puzzle for the same local calendar date. A new one is available at midnight in your device’s time zone. Our first season runs from November 9, 2026 through February 8, 2027.

Unlimited starts with 100 practice puzzles. Daily puzzles enter that pool the day after publication. Today’s Daily and future Daily puzzles are excluded. The game avoids repeats until you have worked through the available pool.

Prices and fund proxies

We independently retrieved historical observations from Yahoo Finance’s chart data in November 2026. Each annual observation is the adjusted close for December’s final trading day. Prices are in US dollars and are adjusted for stock splits and distributions. Adjusted historical prices can be revised by the provider.

The S&P 500 comparison uses the SPDR S&P 500 ETF Trust (SPY) adjusted-price series. This is a fund-based benchmark, including the effect of distributions, rather than the unadjusted S&P 500 price index.

Non-stock options are explicitly identified as funds: Gold (GLD), Silver (SLV), long-term Treasuries (TLT), 7–10-year Treasuries (IEF), crude-oil futures (USO), and a diversified commodities fund (DBC). Fund expenses, distributions and futures-roll effects are reflected in those prices. These are not spot commodity prices. Tap an asset’s picture or name to see its identifier and description.

For example, the original price sources can be inspected on SPY’s historical data and GLD’s historical data. Our selection covers 24 stocks and six other funds, plus cash.

How returns are calculated

Each starting chip buys $1,000 worth of an asset. Holding preserves those units as their prices move. Rebalancing sells every position and redistributes the entire current portfolio in ten equal chips, with at most four chips per option. Cash earns zero. We do not model taxes, transaction costs or trading spreads.

The result shows your five-year value, the SPY comparison and the best possible plan under the same rules. The strategy percentage is calculated across all permitted opening allocations and both hold-or-rebalance decisions. It compares mathematical strategies, not real people. We do not operate a player leaderboard.

Historical clues

Clues are our own short summaries of economic events, with links to the Federal Reserve’s historical records after the reveal. They help you identify the period. A clue is not a claim that one event caused a stock’s return.

Made for a small screen

The portfolio options stay together in a compact list. Chip controls have large touch targets, and the allocation bar stays within reach while you scroll. Help opens only when you choose the question mark.

All asset illustrations and the interface artwork were drawn for this site. They are illustrative symbols, not company logos.

Questions or corrections

Email support@erstwhile.online with a puzzle date or practice ID and the detail you think needs checking.

A quick field guide

Five years. Three decisions.

You have $10,000 in a hidden year between 2005 and 2020. Can you grow it faster than the S&P 500?

  1. 1

    Build your portfolio

    Place 10 chips across four stocks, two other assets and cash. Each chip starts at $1,000. Put up to 4 on any option, including cash.

  2. 2

    Hold or change course

    At years 2 and 4, see your positions and a new historical clue. Hold keeps your actual holdings. Rebalance sells everything: divide the current total into 10 equal chips and place them again.

  3. 3

    See where you landed

    Year 5 reveals the dates, your return and the S&P 500 fund result. See the strongest possible strategy and how your result compares with all legal strategies.

Daily changes at midnight in your device’s local time. Unlimited includes 100 practice puzzles plus previously released Daily puzzles. Gold, silver, oil, bonds and commodities use the fund proxies named in asset details. No fees, taxes or trading costs are simulated.