Try it: https://gold-digger.streamlit.app/
See what your investments are really doing.
Dollars are a rubber ruler. Gold Digger re-prices any stock, ETF, index, or crypto in troy ounces of gold, so you can see whether an asset actually gained purchasing power or just rode the currency's decline.
Since 2015, Apple is up ~1,245% in dollars — but only ~266% in gold. Three-quarters of that "gain" was the measuring stick shrinking.
- Pick a preset asset (SPY, QQQ, AAPL, NVDA, BTC-USD, …) or type any Yahoo Finance ticker
- Set any date window
- Rebased view — the asset in USD, the asset in gold, and gold itself, all starting at 100
- Raw view — ounces of gold one share buys, over time
- Headline metrics: USD return, gold-denominated return, gold's own return, ounces-per-share now
- One plain-English sentence with the verdict
- Commodities: gold, silver, crude oil, copper, wheat, corn, coffee, and live cattle from Yahoo Finance
- Real world: eggs, bacon, regular gasoline, ground beef, and the median US home price from FRED
- Indexes: Bitcoin and the S&P 500 from Yahoo Finance, plus CPI from FRED
- Fun: the US Big Mac price from The Economist's Big Mac Index; approximate and hand-maintained
See what $10,000 invested in SPY, your selected yardstick, or cash under the mattress would be worth today, then compare every yardstick on one leaderboard.
Turn one yardstick into another and see the purchasing power as a literal pile of icons, with a history chart for context. For example, choose one troy ounce of gold and Big Macs, then slide between 2012 and today to watch the burger pile change.
asset_in_yardstick = asset_price_usd / yardstick_price_usd
units = dollars / yardstick_price_at_start
value_today = units * yardstick_price_today
| Yardstick | Category | Unit | Source | Series/ticker | Native frequency | Notes |
|---|---|---|---|---|---|---|
| 🪙 Gold | Commodity | troy ounce | Yahoo Finance | GC=F | Daily | COMEX front-month futures; GLD fallback is an approximate ounce proxy. |
| 🥈 Silver | Commodity | troy ounce | Yahoo Finance | SI=F | Daily | COMEX silver futures, quoted in USD per troy ounce. |
| 🛢️ Crude oil | Commodity | barrel | Yahoo Finance | CL=F | Daily | WTI crude-oil futures, quoted in USD per barrel. |
| 🟠 Copper | Commodity | pound | Yahoo Finance | HG=F | Daily | COMEX copper futures, quoted in USD per pound. |
| 🌾 Wheat | Commodity | bushel | Yahoo Finance | ZW=F | Daily | CBOT wheat futures; cents-per-bushel quotes are converted to USD. |
| 🌽 Corn | Commodity | bushel | Yahoo Finance | ZC=F | Daily | CBOT corn futures; cents-per-bushel quotes are converted to USD. |
| ☕ Coffee | Commodity | pound | Yahoo Finance | KC=F | Daily | Coffee futures; cents-per-pound quotes are converted to USD. |
| 🐄 Live cattle | Commodity | pound | Yahoo Finance | LE=F | Daily | Live-cattle futures; cents-per-pound quotes are converted to USD. |
| ₿ Bitcoin | Index | bitcoin | Yahoo Finance | BTC-USD | Daily | Yahoo Finance BTC-USD adjusted close; trades seven days a week. |
| 📈 S&P 500 | Index | index unit | Yahoo Finance | ^GSPC | Daily | S&P 500 index level from Yahoo Finance. |
| 🥚 Dozen eggs | Real world | dozen eggs | FRED | APU0000708111 | Monthly | US city-average retail price per dozen from FRED. |
| 🥓 Pound of bacon | Real world | pound of bacon | FRED | APU0000704111 | Monthly | US city-average retail price per pound from FRED. |
| ⛽ Regular gasoline | Real world | gallon | FRED | GASREGW | Weekly | US regular gasoline price per gallon from FRED. |
| 🥩 Pound of ground beef | Real world | pound of ground beef | FRED | APU0000703112 | Monthly | US city-average retail price per pound from FRED. |
| 🏠 Median US home | Real world | median home | FRED | MSPUS | Quarterly | Median US home sale price from FRED; one unit is a full median home. |
| 💵 US CPI | Index | dollar of purchasing power as of the start date | FRED | CPIAUCSL | Monthly | CPI is rebased so one unit is a dollar of start-date purchasing power. |
| 🍔 Big Mac | Fun | Big Mac | The Economist Big Mac Index | economist-big-mac-us | ~Semiannual | Approximate US Big Mac price, hand-maintained from The Economist index. |
Lower-frequency FRED and Big Mac observations are expanded and forward-filled, then aligned to business days or the asset's trading-day index for comparisons. Yahoo asset prices use dividend- and split-adjusted closes, and source results are cached for one hour.
Caveats:
- Gold is COMEX front-month futures, not spot gold. The GLD fallback is an approximate proxy and carries an expense ratio.
- FRED grocery prices are US city averages, not a quote from your neighborhood store.
- Big Mac prices are approximate and hand-maintained from The Economist's index.
- The CPI yardstick means a dollar of purchasing power as of the selected start date.
- None of this is investment advice.
git clone https://github.com/ncypher/gold_digger.git
cd gold_digger
pip install -r requirements.txt
streamlit run app.pyOpens at http://localhost:8501.
asset_in_gold = asset_close_usd / gold_close_usd
That's it — ounces of gold per share. Everything else is presentation.
- Gold price: COMEX front-month futures (
GC=F), falling back to theGLDETF if futures history is thin for the window - Asset prices: dividend/split-adjusted closes from Yahoo Finance via
yfinance - Data is cached for one hour per ticker/window
yfinanceis free and unofficial. Fine for a demo; swap in a real market-data provider if this grows legs.- Gold futures ≠ spot, and
GLDcarries an expense ratio. Both are close enough for the purpose here. - This is an analysis toy, not investment advice.
Sparked by a podcast aside — the idea that a stock chart priced in gold shows you something a dollar chart hides. Built in an afternoon to see if it was true. It was.
MIT