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ETF comparison

IVOO vs MDY

Both US Mid Cap.

Vanguard S&P Mid-Cap 400 Index Fund ETF Shares · State Street SPDR S&P MIDCAP 400 ETF Trust

Holdings overlap

Weighted by ISIN/CUSIP
87.5 %

384 positions appear in both funds. Buying equal dollars of IVOO and MDY would leave roughly 87.5% of each dollar exposed to the same underlying securities.

IVOO only 12.4% Shared 87.5% MDY only 12.5%
In IVOO only
18 positions
Shared
384 positions
In MDY only
17 positions

Side by side

IVOO

Vanguard S&P Mid-Cap 400 Index Fund ETF Shares

Vanguard · US Mid Cap

92 composite / 100
Expense ratio
0.070%
Net assets
$5.86B
TTM yield
1.18%
Top-10 conc.
8.3%
MDY

State Street SPDR S&P MIDCAP 400 ETF Trust

State Street · US Mid Cap

88 composite / 100
Expense ratio
0.23%
Net assets
$28.05B
TTM yield
1.02%
Top-10 conc.
7.8%

Sub-score comparison

93
Cost
77
88
Tax efficiency
88
90
Liquidity
100
100
Concentration
100
—
Tracking quality
—
IVOO sub-score MDY

Tracking quality isn't part of the composite — see what we don't score for why.

Cost difference

IVOO is 16 bps cheaper than MDY. On a $100,000 position that's about $160/yr more in fees for MDY.

Fee figure is the annual expense charged on $100,000. To see how the gap compounds over a multi-decade holding period, open the cost calculator pre-filled with IVOO vs MDY.

Top shared holdings

384 shared in total
# Holding In IVOO In MDY Overlap
1 Curtiss-Wright Corp 0.75% 0.78% 0.75%
2 TechnipFMC PLC 0.78% 0.74% 0.74%
3 Woodward Inc 0.67% 0.69% 0.67%
4 XPO Inc 0.72% 0.67% 0.67%
5 ATI Inc 0.64% 0.71% 0.64%
6 United Therapeutics Corp 0.63% 0.65% 0.63%
7 US Foods Holding Corp 0.62% 0.64% 0.62%
8 Illumina Inc 0.60% 0.79% 0.60%
9 Entegris Inc 0.58% 0.62% 0.58%
10 Pure Storage Inc 0.58% 0.64% 0.58%
11 Carpenter Technology Corp 0.57% 0.82% 0.57%
12 nVent Electric PLC 0.55% 0.68% 0.55%

Only in IVOO

18 total
  • Lumentum Holdings Inc 1.44%
  • Coherent Corp 1.18%
  • Casey's General Stores Inc 0.74%
  • Flex Ltd 0.68%
  • EchoStar Corp 0.45%
  • TopBuild Corp 0.36%
  • Masimo Corp 0.23%
  • Janus Henderson Group PLC 0.19%
  • BellRing Brands Inc 0.07%
  • Flowers Foods Inc 0.06%

Only in MDY

17 total
  • U.S. Dollar 0.84%
  • Roku Inc. Class A 0.52%
  • Coeur Mining Inc. 0.50%
  • Toast Inc. Class A 0.37%
  • SiTime Corporation 0.37%
  • Solstice Advanced Materials Inc. 0.35%
  • Semtech Corporation 0.35%
  • Moog Inc. Class A 0.33%
  • Sanmina Corporation 0.33%
  • SharkNinja Inc. 0.30%

Open IVOO or MDY at a brokerage

Both funds trade commission-free at major US brokerages.

Open at Fidelity

Affiliate links — opening an account through these earns PlainIndex a one-time referral. Scoring is computed before any affiliate consideration; see our methodology and funding disclosure.

Holdings overlap is the sum of min(weight_a, weight_b) over positions matched on ISIN (CUSIP fallback). Methodology: see /methodology/.

Comparing two funds doesn't endorse swapping one for the other. Tax-lot history, account type, and personal goals matter — PlainIndex publishes data and methodology, not investment advice.