Equal-Weight ETFs: Smart Diversification or a Drag on Returns?
The ten largest positions now account for roughly a third of the S&P 500 — a concentration level not seen in decades. Equal-weight ETFs promise the way out: all 500 stocks at 0.2% each instead of Magnificent-7 dominance. Whether that is diversification or a drag on returns is answered by twenty years of RSP-versus-SPY history.
RSP vs. SPY: what twenty years of data show
The Invesco S&P 500 Equal Weight (RSP) has existed since 2003 and provides the longest real-world test. The pattern: from 2003 to around 2013 equal weight was clearly ahead, carried by the recovery of smaller names after the dotcom bust. Since the mid-2010s, and especially since the AI rally from 2023, the cap-weighted version has dominated because the very largest stocks drove returns. Over the full period both approaches end up surprisingly close — the difference lies in the timing of cycles, not in structural superiority.
Equal weight is effectively a size and anti-momentum bet: a systematic mid-cap overweight plus regularly selling winners at each rebalance. That makes the strategy rate-sensitive — smaller companies suffer more from high financing costs.
Concentration risks, ETF overlap and look-through analysis – free with MoneyPeak.
Costs, turnover and the silent return drag
The cost disadvantage is real and twofold: a higher TER plus internal trading costs from quarterly rebalancing (far higher turnover than the cap-weighted original, which rebalances itself).
| Criterion | S&P 500 (market cap) | S&P 500 Equal Weight |
|---|---|---|
| TER (UCITS, approx.) | 0.03–0.09% | 0.20–0.25% |
| Top-10 share | around a third | 2% (10 × 0.2%) |
| Sector tilt | tech-heavy | more industrials/financials |
| Turnover | minimal | high (quarterly rebalancing) |
| Factor profile | momentum/mega cap | size/value tilt |
Satellite, not replacement: the sensible dose
As a full core replacement, equal weight is hard to justify: higher costs, higher rate sensitivity, and concentration can also be addressed globally via broader indices. As a 10–20% satellite, however, an equal-weight ETF can cut top-10 dependence in a targeted way: in a €100,000 portfolio with a 35% top-10 share, adding €20,000 of equal weight pushes the effective top-10 share down to roughly 28%. How large your concentration risk really is only becomes visible at look-through level — many portfolios hold the same mega caps across several ETFs, which an overlap analysis reveals.
Frequently asked questions
Does equal weight deliver higher long-term returns?
Over very long periods both approaches end up close. Equal weight wins in mid-cap and recovery phases and loses in mega-cap rallies — the data do not show structural superiority.
Why are equal-weight ETFs more expensive?
Higher TERs (around 0.20–0.25% instead of 0.03–0.09%) plus internal trading costs from quarterly rebalancing with much higher turnover.
How much equal weight makes sense as a satellite?
Typically 10–20% of the equity allocation. That noticeably reduces top-10 concentration without turning the whole portfolio into a size bet.
Concentration risks, ETF overlap and look-through analysis – free with MoneyPeak.