# Portfolio overlap — MBB vs HCASX

Comparing **iShares MBS ETF** (2026-02-28) and **The U.S. Mortgage/Asset Backed Fixed Income Securities Portfolio** (2025-12-31).

- Shared positions: 567
- iShares MBS ETF covered by The U.S. Mortgage/Asset Backed Fixed Income Securities Portfolio: 0.1074240102792591416236050841
- The U.S. Mortgage/Asset Backed Fixed Income Securities Portfolio covered by iShares MBS ETF: 0.1074240102792591416236050841

## iShares MBS ETF — top positions

| Security | Weight | Shared |
|----------|--------|--------|
| BlackRock Cash Funds: Treasury, SL Agency Shares | 0.056553 |  |
| FR SD8146 | 0.010291 | ✓ |
| GNII II 5.5% 03/01/2056 #TBA | 0.009615 |  |
| FNCL 5 3/24 | 0.005482 |  |
| G2 MA7648 | 0.005326 |  |
| G2 MA7766 | 0.005234 | ✓ |
| FN MA4492 | 0.005114 |  |
| G2SF 5 3/25 | 0.005052 |  |
| FR SD8140 | 0.004922 |  |
| FNCL 5.5 3/25 | 0.004759 |  |
| G2 MA7472 | 0.004475 | ✓ |
| Government National Mortgage Association, TBA | 0.004357 |  |
| FN MA4465 | 0.004341 |  |
| Uniform Mortgage-Backed Securities | 0.004292 |  |
| G2 MB0025 | 0.004054 | ✓ |
| G2 MA7935 | 0.003572 | ✓ |
| G2 MA7367 | 0.003481 | ✓ |
| Uniform Mortgage-Backed Security, TBA | 0.003370 |  |
| FR SD8199 | 0.003358 | ✓ |
| FN MA4281 | 0.003206 | ✓ |
| Fannie Mae Pool | 0.003203 |  |
| G2 MA9171 | 0.003146 |  |
| FN MA4437 | 0.003071 | ✓ |
| G2 MA7826 | 0.003026 | ✓ |
| G2 MA7534 | 0.002974 | ✓ |
| FN MA4305 | 0.002901 | ✓ |
| Fannie Mae Pool | 0.002783 |  |
| G2 MA7936 | 0.002780 | ✓ |
| G2 MA7051 | 0.002745 | ✓ |
| G2 MA7767 | 0.002705 | ✓ |
| G2 MA9965 | 0.002625 | ✓ |
| FR SD8324 | 0.002477 |  |
| FNCL 6 3/24 | 0.002438 |  |
| G2 MB0624 | 0.002424 |  |
| FR SD8182 | 0.002333 | ✓ |
| FANNIE MAE POOL FN 05/52 FIXED VAR | 0.002240 |  |
| G2 MA9781 | 0.002239 |  |
| G2 MA7987 | 0.002232 | ✓ |
| G2 MA7589 | 0.002201 | ✓ |
| FR SD8134 | 0.002183 | ✓ |
| FR SD8362 | 0.002174 | ✓ |
| Uniform Mortgage-Backed Securities | 0.002110 |  |
| Uniform Mortgage-Backed Securities | 0.002096 |  |
| FR RA5205 | 0.002096 |  |
| FNCL UMBS 3.0 CA9308 02-01-51 | 0.002061 |  |
| G2 MA9852 | 0.002041 | ✓ |
| Uniform Mortgage-Backed Securities | 0.001978 |  |
| G2 MB0091 | 0.001940 |  |
| Freddie Mac Pool | 0.001921 |  |
| FR SD8234 | 0.001872 |  |

## The U.S. Mortgage/Asset Backed Fixed Income Securities Portfolio — top positions

| Security | Weight | Shared |
|----------|--------|--------|
| Vanguard Scottsdale Funds INTERMEDIATE-TERM TREASURY | 0.116768 |  |
| SS INST TREAS PLUS MM FUN | 0.081281 |  |
| ISHARES US TREASURY BOND ETF | 0.021627 |  |
| FNCL 2 1/26 | 0.007206 |  |
| FNCL 6 1/26 | 0.005361 |  |
| FNCL 2.5 1/26 | 0.005251 |  |
| FNCL 5.5 1/26 | 0.004201 |  |
| FNCL 3 1/26 | 0.003824 |  |
| G2 MA7704 | 0.003093 | ✓ |
| FNCL 4 1/26 | 0.002733 |  |
| G2SF 5 1/26 | 0.002604 |  |
| FNCL 4.5 1/26 | 0.002461 |  |
| G2SF 3 1/26 | 0.002269 |  |
| G2 MB0025 | 0.002210 | ✓ |
| G2 MB0742 | 0.002188 |  |
| G2SF 6 1/25 | 0.002110 |  |
| Government National Mortgage Association, TBA | 0.002099 |  |
| G2 MB0090 | 0.002035 | ✓ |
| G2 MA8428 | 0.002031 |  |
| Uniform Mortgage-Backed Security, TBA | 0.002006 |  |
| FNCL 5 1/26 | 0.001976 |  |
| G2 MA7589 | 0.001975 | ✓ |
| G2 MA7417 | 0.001963 | ✓ |
| G2SF 4 1/26 | 0.001956 |  |
| Freddie Mac Pool | 0.001875 |  |
| FNCL 6.5 1/26 | 0.001872 |  |
| FNCI 2 1/26 | 0.001835 |  |
| Federal National Mortgage Association, Inc. | 0.001824 |  |
| FEDERAL HOME LOAN MORTGAGE CORPORATION | 0.001765 |  |
| FNMA POOL CB7651 FN 12/53 FIXED 6.5 | 0.001752 |  |
| FNCL 3.5 1/26 | 0.001749 |  |
| Uniform Mortgage-Backed Security, TBA | 0.001737 |  |
| G2SF 3.5 1/26 | 0.001721 |  |
| G2 MA8877 | 0.001707 | ✓ |
| G2 MB0092 | 0.001654 | ✓ |
| FR SD8214 | 0.001567 | ✓ |
| FR SD6764 | 0.001567 |  |
| FNMA UMBS, 30 Year | 0.001563 |  |
| G2 MB0145 | 0.001531 | ✓ |
| UMBS | 0.001526 |  |
| G2 MB0146 | 0.001526 | ✓ |
| FN CB9309 | 0.001520 |  |
| FN MA5585 | 0.001515 |  |
| Freddie Mac Pool | 0.001514 |  |
| UMBS | 0.001514 |  |
| FR SD8505 | 0.001510 |  |
| FR SD8491 | 0.001505 | ✓ |
| Federal National Mortgage Association, Inc. | 0.001484 |  |
| FN MA5107 | 0.001476 | ✓ |
| Federal National Mortgage Association, Inc. | 0.001473 |  |


## Sources

- N-PORT (fund A) — accession `0001410368-26-039527` (as of 2026-02-28)
  <https://www.sec.gov/Archives/edgar/data/1100663/000141036826039527/0001410368-26-039527-index.htm>
- N-PORT (fund B) — accession `0001004726-26-001165` (as of 2025-12-31)
  <https://www.sec.gov/Archives/edgar/data/934563/000100472626001165/0001004726-26-001165-index.htm>

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