SEC 13F Intelligence

Managers / Q1 2026

MASON STREET ADVISORS, LLC

CIK 0001167711 · 720 EAST WISCONSIN AVE, MILWAUKEE, WI, 53202 · 4146655400

Reported Value
$1.0B
Q1 2026
Positions
15
Filings on Record
42
2019–present window
Filed
May 7, 2026
original filing

Summary

Mason Street Advisors, Llc reported $1.0B in U.S.-listed holdings across 15 positions for Q1 2026.

The portfolio is heavily concentrated: AGG alone accounts for 29.6% of reported value.

Compared with Q4 2025, the fund opened 2 new positions and exited 2.

Reported Value by Quarter

13F Reported Value
Q4 ’18: $4.0BQ4 ’18Q1 ’19: $4.8BQ2 ’19: $4.7BQ3 ’19: $4.8BQ4 ’19: $5.1BQ4 ’19Q1 ’20: $4.3BQ2 ’20: $4.9BQ3 ’20: $5.1BQ4 ’20: $5.9BQ4 ’20Q1 ’21: $114MQ2 ’21: $111MQ3 ’21: $134MQ4 ’21: $138MQ4 ’21Q1 ’22: $170MQ2 ’22: $286MQ3 ’22: $345MQ4 ’22: $402.1BQ4 ’22Q1 ’23: $452MQ2 ’23: $537MQ3 ’23: $521MQ4 ’23: $545MQ4 ’23Q1 ’24: $594MQ2 ’24: $743MQ3 ’24: $823MQ4 ’24: $773MQ4 ’24Q1 ’25: $786MQ2 ’25: $855MQ3 ’25: $965MQ4 ’25: $1.0BQ4 ’25Q1 ’26: $1.0Bfilingsflow.com

Portfolio Composition

By security type

Composition data arrives with ticker enrichment.

Quarter-over-Quarter Changes full breakdown →

Holdings — Q1 2026

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#IssuerClass% PortfolioValueShares

Filing History

QuarterReported ValuePositionsFiledTypeLinks
Q1 2026$1.0B15May 7, 202613F-HRchanges · EDGAR ↗
Q4 2025$1.0B15Feb 4, 202613F-HRchanges · EDGAR ↗
Q3 2025$965M15Oct 31, 202513F-HRchanges · EDGAR ↗
Q2 2025$855M15Aug 8, 202513F-HRchanges · EDGAR ↗
Q1 2025$786M13May 14, 202513F-HRchanges · EDGAR ↗
Q4 2024$773M12Feb 10, 202513F-HRchanges · EDGAR ↗
Q3 2024$823M12Nov 12, 202413F-HRchanges · EDGAR ↗
Q2 2024$743M12Aug 15, 202413F-HRchanges · EDGAR ↗
Q1 2024$594M8May 15, 202413F-HRchanges · EDGAR ↗
Q4 2023$545M7Feb 13, 202413F-HRchanges · EDGAR ↗
Q3 2023$521M8Nov 14, 202313F-HRchanges · EDGAR ↗
Q2 2023$537M8Aug 14, 202313F-HRchanges · EDGAR ↗
Q1 2023$452M9May 15, 202313F-HRchanges · EDGAR ↗
Q4 2022$402.1B9Feb 21, 202313F-HRchanges · EDGAR ↗
Q3 2022$345M9Nov 14, 202213F-HRchanges · EDGAR ↗
Q2 2022$286M10Aug 15, 202213F-HRchanges · EDGAR ↗
Q1 2022$170M11May 9, 202213F-HRchanges · EDGAR ↗
Q4 2021$138M9Feb 3, 202213F-HRchanges · EDGAR ↗
Q3 2021$134M9Nov 15, 202113F-HRchanges · EDGAR ↗
Q2 2021$111M8Aug 13, 202113F-HRchanges · EDGAR ↗
Q1 2021$114M7May 14, 202113F-HRchanges · EDGAR ↗
Q4 2020$5.9B1,515Feb 12, 202113F-HRchanges · EDGAR ↗
Q3 2020$5.1B1,516Nov 13, 202013F-HRchanges · EDGAR ↗
Q2 2020$4.9B1,516Aug 14, 202013F-HRchanges · EDGAR ↗
Q1 2020$4.3B1,535May 8, 202013F-HRchanges · EDGAR ↗
Q4 2019$5.1B1,516Feb 19, 202013F-HRchanges · EDGAR ↗
Q3 2019$4.8B1,516Nov 5, 201913F-HRchanges · EDGAR ↗
Q2 2019$4.7B1,513Aug 12, 201913F-HRchanges · EDGAR ↗
Q1 2019$4.8B1,560May 7, 201913F-HRchanges · EDGAR ↗
Q4 2018$4.0B1,514Feb 13, 201913F-HRchanges · EDGAR ↗

Other Included Managers

This filing reports holdings on behalf of 24 additional managers.

  • abrdn Investments Ltd028-14936
  • ALLSPRING GLOBAL INVESTMENTS, LLC028-04413
  • AMERICAN CENTURY INVESTMENT MANAGEMENT INC028-01091
  • BLACKROCK ADVISORS LLC028-04295
  • Boston Partners028-12484
  • DODGE & COX028-00400
  • DRIEHAUS CAPITAL MANAGEMENT LLC028-04207
  • EARNEST PARTNERS LLC028-05269
  • FEDERATED INVESTMENT MANAGEMENT CO028-04377
  • FIAM LLC028-12282
  • FRANKLIN MUTUAL ADVISERS LLC028-06154
  • FRANKLIN RESOURCES INC028-00734
  • Invesco Advisers, Inc.028-00255
  • J.P. Morgan Investment Management Inc.028-11937
  • KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC028-05792
  • LOOMIS SAYLES & CO L P028-00398
  • MASSACHUSETTS FINANCIAL SERVICES CO /MA/028-04968
  • Neuberger Berman Investment Advisers LLC028-17085
  • Northern Trust Investments, Inc028-10487
  • PACIFIC INVESTMENT MANAGEMENT CO LLC028-10952
  • T. Rowe Price Investment Management, Inc.028-22690
  • Vaughan Nelson Investment Management, L.P.028-05840
  • WELLINGTON MANAGEMENT GROUP LLP028-04557
  • PRICE T ROWE ASSOCIATES INC /MD/028-00115

13F filings are due up to 45 days after quarter end, so holdings shown here lag the fund’s current book. Source: original SEC filing on EDGAR ↗.