Investing
Investing 100 dollars a month in VOO since 2015
One hundred dollars a month is the amount most people can actually start with, and it is the amount most backtests skip. This page buys 100 dollars of VOO on the first trading day of every month from January 2015, never sells, and reinvests dividends, and reports what that came to on the snapshot date.
Final portfolio value
$37,059.52
Total invested
Absolute profit
Annualized return (IRR)
Max drawdown (MDD)
Compare scenarios
Pin these figures as scenario A, then change any input above to see the difference.
Portfolio value over time
Transaction log
| Date | Price | Investment | Shares | Cost | APB | Total shares | Portfolio |
|---|---|---|---|---|---|---|---|
| 2015-01-02 | $154.78 | $100.00 | 0.6460920797510219 | $100.00 | $154.78 | 0.646 | $100.00 |
| 2015-02-02 | $152.06 | $100.00 | 0.6576459562994262 | $100.00 | $153.41 | 1.304 | $198.24 |
| 2015-03-02 | $159.76 | $100.00 | 0.6259255874624602 | $100.00 | $155.47 | 1.93 | $308.29 |
| 2015-04-01 | $155.72 | $100.00 | 0.6421646600091316 | $100.00 | $155.53 | 2.572 | $400.49 |
| 2015-05-01 | $159.45 | $100.00 | 0.6271664681684794 | $100.00 | $156.30 | 3.199 | $510.07 |
| 2015-06-01 | $160.14 | $100.00 | 0.6244500936362916 | $100.00 | $156.93 | 3.823 | $612.29 |
| 2015-07-01 | $157.85 | $100.00 | 0.6335328961956349 | $100.00 | $157.06 | 4.457 | $703.51 |
| 2015-08-03 | $159.57 | $100.00 | 0.6266822501652874 | $100.00 | $157.37 | 5.084 | $811.20 |
| 2015-09-01 | $145.66 | $100.00 | 0.6865378172491253 | $100.00 | $155.97 | 5.77 | $840.48 |
| 2015-10-01 | $146.95 | $100.00 | 0.6805031095589592 | $100.00 | $155.02 | 6.451 | $947.93 |
Performance summary
| Total return | +162.83% |
|---|---|
| Sharpe ratio | 0.83 |
| Average buy price (APB) | $269.38 |
| Buy & hold final value | $64,498.99 |
| Buy & hold return | +357.44% |
| DCA vs buy & hold | Buy & hold better |
| Final shares | 52.343 |
| Investments | 141 |
| Average per investment | $100.00 |
Past performance is no guarantee of future results. Nothing on this page is investment advice.
The same money invested all at once
Lump sum final value
Monthly plan final value
Difference
The lump sum invests $14,100 — the same capital the monthly plan eventually contributed — at the first closing price of the period and holds it to 2026-09-04. No interest is credited to cash waiting to be invested.
If you had started at the worst possible moment
The worst moment is defined as the high that preceded the deepest fall in this window: VOO closed at $282.47 on 2020-02-19 and then fell 34.0% to $186.45 on 2020-03-23. Daily closing prices throughout. The run below buys the same amount, at the same frequency, starting on that high and holding to 2026-09-04.
Contributed
Final value
Profit
Annualised return
Maximum drawdown
Buying the top is the outcome a lump sum risks and a contribution plan spreads out. The figures above are what that spreading was worth over this window and nothing more.
The same plan on different funds
$100 on the first trading day of each month from 2015-01-02, run to 2026-09-04 on each series in the committed price snapshot.
| Ticker | From | Contributed | Final value | Total return | Annualised | Max drawdown |
|---|---|---|---|---|---|---|
| QQQ | 2015-01-02 | $14,100 | $50,180 | 255.9% | 20.3% | 35.1% |
| SPY | 2015-01-02 | $14,100 | $36,881 | 161.6% | 15.5% | 33.7% |
| VOO | 2015-01-02 | $14,100 | $37,060 | 162.8% | 15.6% | 34.0% |
Every row contributes the same money on the same days, so the columns are directly comparable. Prices as of 2026-09-04. Yahoo Finance chart API — daily adjusted close (dividends reinvested)
Small contributions and the arithmetic of fractional shares
A hundred dollars stopped buying a whole share of VOO years ago, and any simulation that rounds down to whole shares quietly stops investing at that moment while still reporting a plausible looking result. This engine buys fractional shares, so the full contribution is invested every month regardless of the share price, which is also what a modern brokerage does. That detail matters far more at this contribution size than at larger ones. The result above is, in proportional terms, identical to a larger contribution over the same period and the same fund: returns scale, and a plan five times the size would produce five times the balance and exactly the same percentages. What does not scale is the psychological question, which is whether a balance this size feels worth continuing in the years when the market falls. The maximum drawdown reported above answers that in numbers rather than in reassurance, and it is measured on the plan's unit price so that a fresh contribution cannot paper over a decline. The number of purchases is also listed. It is a count of months, which is the only input a contribution plan really has, and over a decade it accumulates into a position that no single contribution could explain on its own.
Why the percentages are the useful part
Read the annualised return and the total return percentage rather than the balance, because the balance is a function of an amount you would probably change. If you can add fifty dollars a month, the honest way to estimate the effect is to scale the totals here, not to hope the percentages improve. The lump sum comparison above shows what the same total capital would have done invested on the first day, which is a useful sanity check on the difference between having money and earning it. For a plan of this size the comparison is close to hypothetical, since nobody starting with a hundred dollars a month had the full amount available in 2015. That is precisely why a contribution plan is the realistic instrument and the lump sum is the benchmark.
Questions about this backtest
Is a hundred dollars a month worth investing at all?
The percentages on this page are the same as they would be for any contribution size in the same fund over the same period. Only the balance changes with the amount.
Does the simulation buy partial shares?
Yes. The whole contribution is invested every month at that day's closing price, so the plan never stalls when the share price passes the contribution amount.
Other backtests worked out
- Investing 500 dollars a month in VOO since 2015
- Investing 500 dollars a month in QQQ since 2015
- Investing 1000 dollars a month in VOO since 2020
Run your own plan in the Dollar-Cost Averaging Calculator and Backtest