SPYM Charges Less Than VOO for the Same S&P 500. Its Long-Term Record Tracks Four Different Indexes

If you sort S&P 500 funds by fee, State Street SPDR Portfolio S&P 500 ETF (NYSEARCA:SPYM) lands near the top, and it wins that spot. State Street Global Advisors lists SPYM’s gross expense ratio at 0.02%. The Vanguard S&P 500 ETF (NYSEARCA:VOO) charges 0.03%. SPYM is the cheaper way to own the index. The cost worth checking sits in a footnote under the performance table, and it is easy to miss.

One Basis Point Separates SPYM From VOO

The two ratios differ by one basis point, or one hundredth of a percentage point. Not something that will dramatically affect performance. A fee is also the easiest fact about a fund to check, which is why so many shoppers stop there.

State Street Global Advisors reports that SPYM held 506 securities as of Oct. 1, 2026. Also, on the same date, the fund reported assets of $173.90 billion and a 30-day median bid-ask spread (the gap between buy and sell quotes) of 0.01%. As such, trading costs are small.

Four Indexes Stitched Into One Performance Record

In State Street Global Advisors’ own words, the benchmark “reflects linked performance returns of the S&P 500 Index, the SSGA Large Cap Index, the Russell 1000 Index, and the Dow Jones U.S. Large-Cap Total Stock Market Index.” State Street Global Advisors dates the fund’s inception to Nov. 8, 2005. The same footnote from State Street Global Advisors lays out the sequence:

• Dow Jones U.S. Large-Cap Total Stock Market Index: inception until 07/09/2013
• Russell 1000 Index: 07/09/2013 until 11/16/2017
• SSGA Large Cap Index, a State Street in-house index: 11/16/2017 until 1/24/2020
• S&P 500 Index: 1/24/2020 to present

Now reread the performance table with that timeline in mind. State Street Global Advisors reports a ten-year average annual NAV total return of 15.36% and a since-inception figure of 11.36%, both as of Aug. 31, 2026. The ten-year window spans three different indexes, including the S&P 500. The since-inception number covers all four. Each had its own components and weighting rules. Comparing that record against VOO’s ten-year number means comparing a stitched series with a decade of S&P 500 tracking.

The recent record is clean. State Street Global Advisors’ one-year NAV total return of 13.11% as of Aug. 31, 2026 falls entirely within the S&P 500 era. Market-price data show the same thing. From Jan. 24, 2020, through Oct. 2, 2026, SPYM’s adjusted price rose 158.75%, compared with 158.39% for VOO. Over the ten years ended on that date, SPYM returned 324.49%, and VOO returned 322.34%. The results are close, but the early years of SPYM’s figure come from different indexes.

Linking benchmark history after an index change is standard, permitted practice. State Street disclosed the changes in plain sight on the fund page and in its performance footnotes.

What Both Funds Really Own

State Street Global Advisors reports that information technology made up 39.94% of SPYM as of Oct. 1, 2026. On the same date, the sponsor listed NVIDIA (NASDAQ:NVDA | NVDA Price Prediction) as the largest holding at 8.44%. That concentration comes from the index, so VOO has essentially the same tech tilt. If your portfolio needs balance, an S&P 500 fund alone won’t provide it.

Where to Find a Fund’s Benchmark Changes Before You Compare

On today’s numbers, SPYM holds a narrow edge over VOO on cost. It tracks the same index with the same holdings, charges a lower stated fee, and has a tight spread. That margin is too thin to decide the choice by itself. Any comparison of SPYM with a rival must consider the fund’s prior index changes.

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