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ETF comparison

IWP vs SPY

US Mid Cap vs US Large Cap.

iShares Russell Mid-Cap Growth ETF · State Street SPDR S&P 500 ETF Trust

Holdings overlap

Weighted by ISIN/CUSIP
4.4 %

82 positions appear in both funds. Buying equal dollars of IWP and SPY would leave roughly 4.4% of each dollar exposed to the same underlying securities.

IWP unmatched 95.5% Shared 4.4% SPY unmatched 95.6%

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
184 positions
Shared
82 positions
In SPY only
423 positions

Side by side

IWP

iShares Russell Mid-Cap Growth ETF

iShares · US Mid Cap

87 composite / 100
Expense ratio
0.23%
Net assets
$19.35B
TTM yield
0.40%
Top-10 conc.
19.7%
SPY

State Street SPDR S&P 500 ETF Trust

State Street · US Large Cap

88 composite / 100
Expense ratio
0.094%
Net assets
$809.22B
TTM yield
1.00%
Top-10 conc.
37.9%

Sub-score comparison

77
Cost
91
90
Tax efficiency
89
100
Liquidity
100
86
Concentration
60
—
Tracking quality
—
IWP sub-score SPY

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

Cost difference

SPY is 14 bps cheaper than IWP. On a $100,000 position that's about $136/yr more in fees for IWP.

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 SPY.

Top shared holdings

82 shared in total
# Holding In IWP In SPY Overlap
1 Marathon Petroleum Corp. 1.05% 0.18% 0.18%
2 Lumentum Holdings, Inc. 1.67% 0.14% 0.14%
3 Datadog, Inc. 2.34% 0.14% 0.14%
4 Robinhood Markets, Inc. 1.75% 0.13% 0.13%
5 Phillips 66 0.11% 0.16% 0.11%
6 Teradyne, Inc. 2.07% 0.11% 0.11%
7 United Rentals, Inc. 0.45% 0.10% 0.10%
8 Coherent Corp. 0.40% 0.10% 0.10%
9 Keysight Technologies, Inc. 0.93% 0.10% 0.10%
10 Simon Property Group, Inc. 1.96% 0.10% 0.10%
11 Comfort Systems USA, Inc. 1.89% 0.09% 0.09%
12 Targa Resources Corp. 1.56% 0.09% 0.09%

Only in IWP

184 total
  • Snowflake, Inc. 2.33%
  • Cloudflare, Inc. 2.12%
  • Astera Labs, Inc. 2.02%
  • Rocket Lab Corp. 1.49%
  • Royal Caribbean Cruises Ltd. 1.24%
  • Credo Technology Group Holding Ltd. 1.23%
  • Alnylam Pharmaceuticals, Inc. 1.10%
  • Natera, Inc. 1.01%
  • Anglogold Ashanti plc 1.01%
  • Revolution Medicines, Inc. 0.98%

Only in SPY

423 total
  • NVIDIA CORP 8.50%
  • APPLE INC 7.32%
  • MICROSOFT CORP 5.77%
  • AMAZON.COM INC 3.71%
  • ALPHABET INC CL A 3.03%
  • BROADCOM INC 2.54%
  • ALPHABET INC CL C 2.43%
  • META PLATFORMS INC CLASS A 2.41%
  • MICRON TECHNOLOGY INC 1.82%
  • TESLA INC 1.57%

Percentages are holdings overlap with the named fund.

Open IWP or SPY 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.