MBB vs IUSB overlap
MBB and IUSB overlap 9.0% by weight, across 1,215 shared holdings.
Pick 2 to 4 ETFs.
These funds report on different dates (MBB: May 31, 2026, IUSB: July 31, 2026), so market moves and index changes between those dates lower the number. Funds tracking the same index can read well below their true overlap.
Top shared holdings
| Holding | MBB | IUSB | Overlap |
|---|---|---|---|
| G2 Ma7192G2 | 0.16% | 0.18% | 0.16% |
| FN Ma4325 | 0.12% | 0.12% | 0.12% |
| FR Sd8469 | 0.11% | 0.11% | 0.11% |
| G2 Ma7534 | 0.30% | 0.09% | 0.09% |
| Freddie Mac Pool | 0.12% | 0.08% | 0.08% |
| FN Ma4281 | 0.33% | 0.08% | 0.08% |
| FR Sd8199 | 0.18% | 0.08% | 0.08% |
| FN Ma4578 | 0.17% | 0.08% | 0.08% |
| G2 Ma9171 | 0.41% | 0.08% | 0.08% |
| G2 Mb0025 | 0.55% | 0.08% | 0.08% |
| G2 Ma7766 | 0.53% | 0.07% | 0.07% |
| FN Ma4493 | 0.13% | 0.07% | 0.07% |
| G2 Mb0872 | 0.13% | 0.07% | 0.07% |
| Fannie Mae Pool | 0.44% | 0.07% | 0.07% |
| Freddie Mac Pool | 0.07% | 0.07% | 0.07% |
Overlap by weight adds up the smaller weight of each holding the funds share, so 100% means identical portfolios. Long securities only: derivatives and cash vehicles are left out. Sources: MBB, SEC Form N-PORT, May 31, 2026; IUSB, SEC Form N-PORT, July 31, 2026.
Largest institutions holding both
| Firm | MBB | IUSB |
|---|---|---|
| Envestnet Asset Management Inc. | $2.9B | $8.3B |
| Bank of America Corp. | $6.5B | $211.6M |
| LPL Financial LLC | $2.6B | $2.9B |
| JPMorgan Chase & Co | $3.6B | $1.0B |
| Jones Financial Companies LLLP | $6.3M | $4.1B |
| BlackRock, Inc. | $218.5M | $3.8B |
| Wells Fargo & Company | $275.3M | $2.3B |
| Morgan Stanley | $1.1B | $1.4B |
| Ameriprise Financial Inc. | $1.3B | $601.3M |
| UBS Group AG | $1.7B | $129.3M |
| Northwestern Mutual Wealth Management Co | $9.1M | $1.5B |
| TIAA Wealth Investment Management LLC | $1.4B | $2K |
| Envestnet Portfolio Solutions, Inc. | $200.3M | $781.7M |
| Mariner, LLC | $7.0M | $957.3M |
| Bank of New York Mellon Corp | $228.8M | $663.7M |
This compares who owns the funds, not what the funds hold. From SEC Form 13F, for managers with $100M+ in US securities.
Who owns them: MBB institutional holders, IUSB institutional holders.
Frequently asked questions
How much do MBB and IUSB overlap?
9.0% by weight, with 1,215 holdings in common, using holdings for MBB as of May 31, 2026 and IUSB as of July 31, 2026. The largest shared position is G2.
Do institutions hold both MBB and IUSB?
565 Form 13F filers report positions in both, out of 1,320 that report either one.
How is overlap by weight worked out?
For each holding the two funds share, take the smaller of the two weights, then add those up. Identical portfolios score 100%.