The question
What if I invested the money I spent on my car?
Treat a round $150/week as a car payment and put it in the S&P 500 since 2018. A proxy for “the car,” not a used-car price index.
Quick answer
If you invested $500/week into S&P 500 from 2018-01-05 through 2026-10-16, total contributions would have been about $229,500 and a blind DCA portfolio would be worth about $433,288 (+88.8%) on this historical path — before fees and taxes.
Assumptions
What this page actually assumes
- $150/week stands in for a car payment — insurance, fuel, and the loan mashed into one round number. We do not have a table of actual car prices.
- That cash buys the S&P 500 every week and is never sold.
- Default start is 2018 (a typical loan window). 2015 is available if you want a longer habit.
- This is not advice to skip owning a car.
Historical data
2018-01-05 → 2026-10-16
Same S&P 500 Friday series as the other stories. Shorter starts mean fewer payments and less time in the market. There is no CPI car-depreciation overlay.
Series: S&P 500. Same contribution calendar. No data before 2015.
Interactive simulation
Change the habit, stay on the real curve
$500/week · S&P 500
2018-01-05 → 2026-10-16 · $500/week · S&P 500
Contributed$229,500Held to the last date$433,288Return+88.8%S&P 5002018-01-05 → 2026-10-16 · $500/week+$203,788 vs cash inEnded $433,288 on $229,500 contributedPortfolio (DCA)Cash contributedResults
What the numbers say
Ending value is “what those payments became if they had been index shares.” Compare it to what you actually got from the car: transport, not a return.
The chart marks portfolio value over time for fixed-amount DCA and (when shown) a same-capital lump sum. Contributed cash rises in steps; ending value is mark-to-market on the last date (2026-10-16).
What changes if…
How did we calculate this?
- Window: real market history from our published backtest bundle, typically from 2015 through the latest Friday in the series — we do not invent older decades.
- Contribution calendar: the engine runs on a weekly Friday grid. A “monthly” habit is converted to an equivalent weekly cash rate ((amount × 12) / 52) so the same engine can compare habits.
- Purchase timing: each period’s contribution is applied on that week’s bar in the series (close-based weekly path), not an intraday open fill.
- Assets: S&P 500, Bitcoin, and other series we publish — USD only. No FX conversion.
- Shares: fractional units are assumed. No brokerage commissions, bid–ask, or slippage are modeled.
- Dividends / income: returns follow the wealth path in the backtest bundle for that asset (not a fixed 7–10% toy rate).
- Lump sum (when shown): the same total cash as the DCA habit, invested on day one of the window, then marked to the same path.
Frequently asked questions
- What if I invested the money I spent on my car?
- From 2018-01-05 to 2026-10-16, $500/week into S&P 500 contributed about $229,500 and a blind DCA habit ended near $433,288 (+88.8%).
- Are these numbers a forecast?
- No. They replay published market history from 2015 onward. Future returns can look nothing like this window.
- What assumptions matter most?
- Start date, contribution size, weekly vs monthly cadence, and whether you held through drawdowns. Fees and taxes are not modeled.
- Can I change the amount or start year?
- Yes — use the chips on this page when available, or open a related what-if / calculator with a different habit.
- How is this different from a 7% compound calculator?
- Fixed-rate toys assume a smooth return. We mark contributions to a real index/crypto path, including crashes in the window.
- What if I had traded instead?
- See The Boring Alternative for story-shaped counterfactuals (options losses, round-trips), then run the same dollars through an index DCA calculator.
Run a related reality check
Same contribution schedule, different assets — or a fixed-rate planning calculator when you want an illustration instead of history.
What if?