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ETF comparison

IWP vs MDY

Both US Mid Cap.

iShares Russell Mid-Cap Growth ETF · State Street SPDR S&P MIDCAP 400 ETF Trust

Holdings overlap

Weighted by ISIN/CUSIP
15.6 %

97 positions appear in both funds. Buying equal dollars of IWP and MDY would leave roughly 15.6% of each dollar exposed to the same underlying securities.

IWP unmatched 84.3% Shared 15.6% MDY unmatched 84.4%

Unmatched is the part of a fund's weight the other fund doesn't match: names only it holds, plus any extra weight it puts in names both funds hold.

In IWP only
169 positions
Shared
97 positions
In MDY only
304 positions

Side by side

IWP

iShares Russell Mid-Cap Growth ETF

iShares · US Mid Cap

87 composite / 100
Expense ratio
0.23%
Net assets
$18.51B
TTM yield
0.41%
Top-10 conc.
19.7%
MDY

State Street SPDR S&P MIDCAP 400 ETF Trust

State Street · US Mid Cap

88 composite / 100
Expense ratio
0.23%
Net assets
$25.95B
TTM yield
1.04%
Top-10 conc.
7.2%

Sub-score comparison

77
Cost
77
90
Tax efficiency
88
100
Liquidity
100
86
Concentration
100
—
Tracking quality
—
IWP sub-score MDY

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

Cost difference

Expense ratios are effectively identical (0.23% vs 0.23%).

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 IWP vs MDY.

Top shared holdings

97 shared in total
# Holding In IWP In MDY Overlap
1 ATI, Inc. 0.73% 0.70% 0.70%
2 XPO, Inc. 0.64% 0.63% 0.63%
3 Woodward, Inc. 0.69% 0.55% 0.55%
4 Roku, Inc. 0.47% 0.62% 0.47%
5 Burlington Stores, Inc. 0.54% 0.47% 0.47%
6 MACOM Technology Solutions Holdings, Inc. 0.70% 0.46% 0.46%
7 Lattice Semiconductor Corp. 0.57% 0.44% 0.44%
8 Carpenter Technology Corp. 0.81% 0.41% 0.41%
9 Neurocrine Biosciences, Inc. 0.39% 0.48% 0.39%
10 Curtiss-Wright Corp. 0.39% 0.48% 0.39%
11 Toast, Inc. 0.36% 0.52% 0.36%
12 Medpace Holdings, Inc. 0.33% 0.43% 0.33%

Only in IWP

169 total
  • Datadog, Inc. 2.34%
  • Snowflake, Inc. 2.33%
  • Cloudflare, Inc. 2.12%
  • Teradyne, Inc. 2.07%
  • Astera Labs, Inc. 2.02%
  • Simon Property Group, Inc. 1.96%
  • Comfort Systems USA, Inc. 1.89%
  • Robinhood Markets, Inc. 1.75%
  • Lumentum Holdings, Inc. 1.67%
  • Targa Resources Corp. 1.56%

Only in MDY

304 total
  • U.S. Dollar 0.77%
  • United Therapeutics Corporation 0.75%
  • TechnipFMC plc 0.72%
  • US Foods Holding Corp. 0.68%
  • Tenet Healthcare Corporation 0.67%
  • Reliance Inc. 0.65%
  • Royal Gold Inc. 0.60%
  • Roivant Sciences Ltd. 0.59%
  • TD SYNNEX Corporation 0.53%
  • East West Bancorp Inc. 0.53%

Percentages are holdings overlap with the named fund.

Open IWP or MDY at a brokerage

Both funds trade commission-free at major US brokerages.

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.