Investors have poured roughly $56.75 billion into the State Street SPDR Portfolio S&P 500 ETF (SPYM) in 2026, pushing the fund past $170.5 billion in assets. The draw is a fee gap against the older SPY fund, plus a structural edge in how each fund handles dividends.
Investors poured roughly $56.75 billion into SPYM so far in 2026, including about $5.2 billion over the latest month. That lifted the fund beyond $170.5 billion in assets. SPYM tracks the same S&P 500 index that SPY has followed since 1993, but the two funds now serve different jobs for investors.
Same index, different cost
SPYM charges 0.02% against SPY's 0.0945%, and it is structured as an open-end fund rather than a unit investment trust. Both funds hold nearly identical portfolios: SPYM's largest position is Nvidia at 8%, and SPY carries Nvidia at the same weight.
Because the holdings match, the difference comes down to structure. SPY's unit-investment-trust setup forbids reinvesting dividends internally or lending securities, so cash sits uninvested until the next quarterly distribution. SPYM, as an open-end fund, can reinvest dividends immediately and lend securities, edges that compound over a long holding period alongside its lower fee.
What the fee gap is worth
The expense difference works out to $74.50 per $100,000 invested per year — trivial on its own, but compounding over decades. SPYM returned about 21% over the trailing year and 14% year to date, with longer stretches of about 84% over five years and 318% over ten years on a dividend-adjusted basis.
Vanguard's VOO and iShares' IVV sit in the same territory on fees and are equally viable core holdings; the choice among the three often comes down to brokerage access and commission-free trading. SPY, meanwhile, still controls roughly $808.5 billion in assets, and that scale keeps it central to options trading, index arbitrage, and institutional hedging, where tight spreads and deep books matter more than a fee gap.
Trump Accounts add a new inflow source
SPYM was named the default investment for the new Trump Accounts on July 1, a move that should generate durable contributions from millions of young accounts, though most of this year's $57 billion arrived before that program began. The fund carries a trailing-twelve-month dividend of roughly $0.91 per share, distributed quarterly, matching SPY's dividend character.
Source: 24/7 Wall St.
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