ETF comparison

AGGvsMBB

Both US Aggregate Bond.

iShares Core U.S. Aggregate Bond ETF · iShares MBS ETF

Holdings overlap

Weighted by ISIN/CUSIP
17.4%

1,879 positions appear in both funds. Buying equal dollars of AGG and MBB would leave roughly17.4%of each dollar exposed to the same underlying securities.

AGG only 81.7%Shared 17.4%MBB only 87.5%
In AGG only
11,388 positions
Shared
1,879 positions
In MBB only
9,266 positions

Side by side

AGG

iShares Core U.S. Aggregate Bond ETF

iShares · US Aggregate Bond

89composite / 100
Expense ratio
0.030%
Net assets
$138.32B
TTM yield
4.12%
Top-10 conc.
6.6%
MBB

iShares MBS ETF

iShares · US Aggregate Bond

88composite / 100
Expense ratio
0.040%
Net assets
$39.63B
TTM yield
4.42%
Top-10 conc.
13.1%

Sub-score comparison

97
Cost
96
52
Tax efficiency
52
100
Liquidity
100
100
Concentration
96
Tracking quality
AGGsub-scoreMBB

Tracking quality isn't part of the composite — seewhat we don't scorefor why.

Cost difference

AGG is 1 bps cheaper than MBB. On a $100,000 position that's about $10/yr more in fees for MBB.

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

Top shared holdings

1,879 shared in total
#HoldingIn AGGIn MBBOverlap
1BlackRock Funds III0.62%6.77%0.62%
2Fannie Mae0.22%0.31%0.22%
3UMBS, TBA0.20%0.34%0.20%
4UMBS, TBA0.16%0.64%0.16%
5Government National Mortgage Association0.14%0.95%0.14%
6Freddie Mac0.14%0.18%0.14%
7Government National Mortgage Association0.14%0.35%0.14%
8UMBS, TBA0.14%0.83%0.14%
9Fannie Mae0.13%0.44%0.13%
10Fannie Mae0.13%0.52%0.13%
11Government National Mortgage Association0.12%0.20%0.12%
12Government National Mortgage Association0.12%0.67%0.12%

Only in AGG

11,388 total
  • United States Treasury0.42%
  • United States Treasury0.41%
  • United States Treasury0.41%
  • United States Treasury0.40%
  • United States Treasury0.40%
  • United States Treasury0.39%
  • United States Treasury0.39%
  • United States Treasury0.39%
  • United States Treasury0.39%
  • United States Treasury0.38%

Only in MBB

9,266 total
  • Fannie Mae0.33%
  • Fannie Mae0.28%
  • Fannie Mae0.23%
  • Fannie Mae0.21%
  • Freddie Mac0.20%
  • Freddie Mac0.19%
  • Fannie Mae0.17%
  • Fannie Mae0.17%
  • Fannie Mae0.16%
  • Freddie Mac0.15%

Open AGG or MBB 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 methodologyand 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.