One of These S&P 500 Funds Has Trailed for 10 Years. Its Fans Say That’s the Point.

Trey Thoelcke

Wed, September 23, 2026 at 4:10 PM GMT+3 4 min read

Quick Read

SPYM's cap-weighted structure delivered +323% over 10 years versus RSP's +203%, as mega-cap tech giants automatically captured more capital with every gain.
Apple alone holds 6.59% of SPYM's $154 billion in assets, making it a concentrated mega-cap bet disguised as broad market diversification.
RSP weights all 500 stocks equally and tilts toward industrials and financials, only outperforming SPYM when mega-cap tech leadership durably fades.
Two retirees, same $1 million, same 4% rule, buy one finished with $1.4 million, the other hit $0 in 12 years. Our free reader guide explains the flaw that separated them, and the income-first method built to avoid it.

Two funds hold nearly identical rosters of large American companies drawn from the same S&P benchmark. The only meaningful difference between SPDR Portfolio S&P 500 ETF (NYSEARCA:SPYM) and Invesco S&P 500 Equal Weight ETF (NYSEARCA:RSP) is how much of each name they own. That single choice has produced a decade of divergent returns, and the very reason SPYM won is why its owners should look closely at what they hold.

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Scoreboard as of September 23, 2026

SPYM last traded at $91.12, and RSP at $212.70, both delayed intraday marks pulled on Wednesday morning. Both funds have a full decade of price history on record, so every window below is a clean, like-for-like comparison.

SPYM leads across every window, and the separation widens over longer horizons. The one-month column shows the gap still opening in real time.

Why the Cap-Weighted Fund Won

SPYM weights each S&P 500 constituent by market capitalization, so the biggest companies drive the bulk of returns. The N-PORT filing dated June 30, 2026, shows Apple alone at 6.59% of net assets, worth roughly $10.1 billion inside a fund carrying $153.9 billion in total net assets. Amazon added 3.62%, Alphabet's two share classes combined for more, and Broadcom at 2.77%.

The 4% Rule is Broken, Built On A World That No Longer Exists

Every retiree knows about the 4% rule, but it frames retirement as a slow liquidation and still causes retirees with seven-figure accounts to agonize over a dinner out.

There's a different way to run the math that makes more sense today. Build an income floor — dividends, interest, and Social Security that cover your essential bills every month — and you never have to sell shares into a down market just to pay them.

Our free reader guide, The 4% Rule Is Broken, walks through it in about 15 minutes. Access the report here.

That is the whole story of the past decade. A handful of mega-cap technology and platform businesses grew faster than everything else, and a cap-weighted vehicle automatically fed more capital into the winners. It is also an uncomfortable truth for anyone using SPYM as a broad-market anchor: this fund is a concentrated bet on a very short list of names, dressed as diversification.

What RSP Is Built to Do

RSP tracks the S&P 500 Equal Weight Index, holding every constituent at roughly the same weight and rebalancing quarterly. Apple carries the same weight as the 400th name in the index. The construction deliberately underweights mega-cap tech and tilts toward industrials, financials, materials, and real estate. In a decade led by the largest platforms, that design was always going to trail.

RSP also throws off cash. It paid a $0.7951 distribution on September 21, 2026, its 93rd quarterly payment on record, and its trailing 12-month distributions totaled $3.18. Total return closes some of the price gap, though the one-month reading suggests the divergence is still widening.

Verdict

A long-horizon investor who wants the S&P 500 as it actually exists today—cap-weighted, concentrated at the top, and technology-heavy—will lean toward SPYM. Its decade of leadership is a direct product of that structure. The investor who wants meaningful exposure to the other 490 companies and can accept long stretches of trailing the headline index will favor RSP.

What could flip the calculus is a durable rotation away from mega-cap leadership. Until that shows up in the numbers, SPYM keeps winning and RSP keeps being exactly what its fans wanted: the more diversified of the two.

Before Your Next Withdrawal, Run One Number ( It's Not The 4% Rule Everyone Knows)

Take your essential monthly expenses and subtract your guaranteed income — Social Security, plus any pension. What's left is your income gap, and how you close it determines whether retirement runs on share sales or on a paycheck your portfolio writes you every month. Our free reader guide, The 4% Rule Is Broken, shows exactly how to close that gap with portfolio income: a worked example (one retiree needed about $480,000 in income-producing assets to cover his essentials for good), an eight-point conversion checklist, and the 20-year numbers comparing dividends to withdrawals. It's free and takes about 15 minutes to read. Get the guide here before you take your next withdrawal.

Contact editorial@247wallst.com for any questions or corrections.