MBB holdings — iShares MBS ETF

iShares MBS ETF (MBB) held 11,146 positions with net assets of $38.7B as of May 31, 2026, according to its Form N-PORT report to the SEC. Its top 10 holdings make up 13.1% of the fund, led by BLACKROCK CASH FUNDS, Freddie Mac, Government National Mortgage Association.

MBB top holdings

  1. BLACKROCK CASH FUNDS — 6.77% ($2.62B)
  2. Freddie Mac — 1.05% ($406M)
  3. Government National Mortgage Association — 0.95% ($367M)
  4. UMBS, TBA — 0.83% ($322M)
  5. Government National Mortgage Association — 0.67% ($260M)
  6. UMBS, TBA — 0.64% ($249M)
  7. Government National Mortgage Association — 0.55% ($213M)
  8. Government National Mortgage Association — 0.54% ($210M)
  9. Government National Mortgage Association — 0.53% ($206M)
  10. Fannie Mae — 0.52% ($202M)
  11. Freddie Mac — 0.50% ($194M)
  12. Government National Mortgage Association — 0.46% ($177M)
  13. Government National Mortgage Association — 0.45% ($176M)
  14. Fannie Mae — 0.44% ($172M)
  15. Fannie Mae — 0.44% ($169M)
  16. Government National Mortgage Association — 0.41% ($159M)
  17. Government National Mortgage Association — 0.36% ($141M)
  18. Government National Mortgage Association — 0.35% ($137M)
  19. UMBS, TBA — 0.34% ($130M)
  20. Fannie Mae — 0.33% ($127M)
  21. Fannie Mae — 0.33% ($127M)
  22. Fannie Mae — 0.31% ($121M)
  23. Government National Mortgage Association — 0.31% ($120M)
  24. Government National Mortgage Association — 0.30% ($117M)
  25. Fannie Mae — 0.30% ($115M)

What are MBB's top 10 holdings?

BLACKROCK CASH FUNDS (6.8%), Freddie Mac (1.0%), Government National Mortgage Association (0.9%), UMBS, TBA (0.8%), Government National Mortgage Association (0.7%), UMBS, TBA (0.6%), Government National Mortgage Association (0.5%), Government National Mortgage Association (0.5%), Government National Mortgage Association (0.5%), Fannie Mae (0.5%).

How many stocks are in MBB?

iShares MBS ETF reported 11,146 holdings as of May 31, 2026.

All ETF and mutual fund holdings