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MDY · State Street SPDR S&P MidCap 400SM ETF Trust ETF

Alerts for MDY
$691.52 +0.88 (+0.13%) At close · Sep 4

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 1,518
Total Value: $18,027,449,631
Total Shares: 25,694,651
Showing 1–100 of 1,536 holdings by value · page 1 of 16

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 1,518 13F filers · Δ vs Mar 31, 2026
Top Holder
7.6%
Sep 2023 → Jun 2026 · range 7.5% – 9.6%
−0.3 pts
Top 5
24.9%
Sep 2023 → Jun 2026 · range 24.4% – 30.5%
−1.4 pts
Top 10
40.5%
Sep 2023 → Jun 2026 · range 38.9% – 44.6%
−1.0 pts
HHI
218
Sep 2023 → Jun 2026 · range 214 – 277
Broadly held−14

Quarterly Activity

vs Mar 31, 2026
New
148
Increased
344
Decreased
533
Sold Out
88
Unchanged
493
Holder count: +60
Institutional value: +12.8%
Shares held: -1.1%

Top Buyers

vs Mar 31, 2026
Institution Added Now Holds Open

Top Sellers

vs Mar 31, 2026
Institution Sold Now Holds Open

Top New Positions

vs Mar 31, 2026
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Mar 31, 2026
Institution Previously Held Last Value (USD) Open
Showing 100 of 1,536
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Holder Value (USD) % of 13F Shares Open