QQQ 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 (Mar 1999 → Oct 2026, $33,200 invested each). Every number below is computed from real daily closes; nothing is annualized away or cherry-picked.
Verdict on this window: $33,200 invested into QQQ grew to $425,211, versus $209,483 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 ($33,200 total), the two curves are what QQQ 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 Oct 2026, refreshed daily.
Concentration versus the whole market
QQQ is a ~100-stock bet dominated by mega-cap tech; SPY spreads across 500 names and every sector. Since this shared window opens in 1999, it contains both halves of the story: QQQ losing ~83% in the dot-com crash and needing fifteen years to reclaim its high, then repricing violently upward through the cloud and AI eras. That's why QQQ's best and worst 5-year windows in the table sit so much further apart.
The trailing-decade verdict flatters QQQ because the recent regime favored exactly what it concentrates in. The rolling head-to-head is the honest lens: it shows how often that concentration won across ALL start months, not just the friendliest one. Higher ceiling, deeper craters — the plan you can hold through 2000–2015 is the one that counts.
FAQ
On the shared window measured here, QQQ finished ahead (QQQ: +1181% vs SPY: +531% 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 QQQ and SPY, compared strictly over their shared history (Mar 1999 → Oct 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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