VOO vs SPY: The DCA Backtest
The identical plan — $100 on the first trading day of each month — run on both assets over their shared history (Sep 2010 → Aug 2026, $19,200 invested each). Every number below is computed from real daily closes; nothing is annualized away or cherry-picked.
Verdict on this window: $19,200 invested into VOO grew to $71,319, versus $71,026 in SPY. Different start dates shuffle this result — the rolling analysis below shows how often.
The same $100/month, side by side
Both positions month by month across the shared window: the dashed line is cash paid in ($19,200 total), the two curves are what VOO and SPY were worth along the way. Where the curves separate is where the decade's story lives.
Does the winner depend on when you started?
One full-window result can mislead — maybe the winner just had a better final year. So we ran the head-to-head across EVERY possible 5-year start month in the shared history:
Side-by-side numbers
Data through Aug 2026, refreshed daily.
The same index in two wrappers
VOO and SPY track the identical S&P 500 index, so this comparison is really about plumbing, not performance: VOO charges 0.03% against SPY's 0.09%, and structural quirks (SPY's older unit-trust structure can't reinvest internal dividends between distributions) add a few more basis points of drift. On a monthly DCA the curves are near-identical — the gap you see compounds from fees, not skill.
For a long-horizon DCA plan the cheaper wrapper wins by default; SPY's edge is liquidity that matters to options traders, not monthly buyers. If you already hold SPY, the switch itself can cost more in realized taxes than the fee gap returns — start new money in the cheaper fund instead.
FAQ
On the shared window measured here, VOO finished ahead (VOO: +271% vs SPY: +270% on identical monthly buys). "Better" is window-dependent — the rolling head-to-head above tells you how stable that verdict was. Past performance doesn't predict the future; this page tells you what happened, not what will.
Yes, and if the pair is highly correlated the blend will behave like either one alone — check how similar the two curves above are before assuming a split adds diversification. Our portfolio calculator lets you backtest any weighting of the two on the same real data.
Real dividend- and split-adjusted daily closes for VOO and SPY, compared strictly over their shared history (Sep 2010 → Aug 2026), refreshed daily and validated for gaps and staleness. Fees, spreads and taxes are not modelled — see the methodology page.
Run the plan on a real exchange
Five exchanges where DCA — and tokenized stocks & ETFs — actually work, each with a real discount. Pick one, copy the code, trade cheaper.
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