MASON STREET ADVISORS, LLC — 13F Holdings & Portfolio
CIK 1167711 · latest 13F-HR filed 2026-08-12
MASON STREET ADVISORS, LLC manages $1.11B in 13F-reported U.S. long-equity assets across 15 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are AGG (27.21%), IVV (13.93%), SPTL (9.47%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 1 new position and exited 1; 9 existing positions rose in reported value and 0 fell.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
Long-equity book
Distinct positions
Filed 2026-08-12
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q2 26Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q1 26 → Q2 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
3 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 90.6%Cumulative share of the portfolio held in the largest N positions.
As of the firm’s regulatory filing dated Mar 31, 2026.
MILWAUKEE, WI 53202-4797
| Name | Title / Status | Ownership | Type |
|---|---|---|---|
| Leritz, Lynn, Phidej Control | DIRECTOR since Mar 2026 | Less than 5% | Individual |
| MIKELSON, PAUL, ANTHONY Control | PRESIDENT & DIRECTOR since Nov 2024 | Less than 5% | Individual |
| SCHUTTE, BRENT, GREGORY Control | CHIEF INVESTMENT OFFICER & DIRECTOR since Dec 2021 | Less than 5% | Individual |
| THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY Control | PARENT COMPANY since May 2001 | 75% or more | Domestic Entity |
| TOMCZAK, BONNIE, LYNN Control | CHAIR & DIRECTOR OF THE BOARD since Nov 2021 | Less than 5% | Individual |
| Gabrys, Matthew, Eugene | CHIEF COMPLIANCE OFFICER since Mar 2026 | Less than 5% | Individual |
| HEISTAD, ANDREW, JOHN | TREASURER since Apr 2022 | Less than 5% | Individual |
Ownership & leadership changes · 16 filings with changes since Mar 28, 2012
From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.
- No longer listedCONMEY, MICHAEL, JORDAN · CHIEF COMPLIANCE OFFICER · Less than 5% · listed since Jun 2020
- No longer listedDRURY, DAVID, JOHN · DIRECTOR · Less than 5% · control person · listed since Nov 2020
- AddedGabrys, Matthew, Eugene · CHIEF COMPLIANCE OFFICER · Less than 5%
- AddedLeritz, Lynn, Phidej · DIRECTOR · Less than 5% · control person
- ChangedTOMCZAK, BONNIE, LYNN · title CHAIRMAN OF THE BOARD → CHAIR & DIRECTOR OF THE BOARD
- No longer listedBENTLEY, JOHN, EMERSON · CHAIRMAN OF THE BOARD · Less than 5% · control person · listed since Dec 2022
- Listed againMIKELSON, PAUL, ANTHONY · PRESIDENT & DIRECTOR · Less than 5% · control person
- ChangedTOMCZAK, BONNIE, LYNN · title PRESIDENT & DIRECTOR → CHAIRMAN OF THE BOARD
- No longer listedJOELSON, RONALD, PETER · CHAIRMAN OF THE BOARD · Less than 5% · control person · listed since Sep 2019
- Listed againBENTLEY, JOHN, EMERSON · CHAIRMAN OF THE BOARD · Less than 5% · control person
- No longer listedMIKELSON, PAUL, ANTHONY · TREASURER · Less than 5% · listed since Jan 2022
- No longer listedSchoenborn, Evamarie · DIRECTOR · Less than 5% · control person · listed since Jan 2022
- Listed againHEISTAD, ANDREW, JOHN · TREASURER · Less than 5%
- ChangedSCHUTTE, BRENT, GREGORY · title CHIEF INVESTMENT OFFICER → CHIEF INVESTMENT OFFICER & DIRECTOR
- No longer listedKROPP, ROSANNE, LEA · DIRECTOR & TREASURER · Less than 5% · control person · listed since Nov 2020
- AddedMIKELSON, PAUL, ANTHONY · TREASURER · Less than 5%
- AddedSchoenborn, Evamarie · DIRECTOR · Less than 5% · control person
- No longer listedFLEMING, KATE, MARIE · PRESIDENT, DIRECTOR & TREASURER · Less than 5% · control person · listed since Jan 2004
- AddedSCHUTTE, BRENT, GREGORY · CHIEF INVESTMENT OFFICER · Less than 5% · control person
- AddedTOMCZAK, BONNIE, LYNN · PRESIDENT & DIRECTOR · Less than 5% · control person
- ChangedKROPP, ROSANNE, LEA · title DIRECTOR → DIRECTOR & TREASURER
- No longer listedHEISTAD, ANDREW, JOHN · VICE PRESIDENT AND TREASURER · Less than 5% · listed since Jan 2015
- AddedDRURY, DAVID, JOHN · DIRECTOR · Less than 5% · control person
- AddedKROPP, ROSANNE, LEA · DIRECTOR · Less than 5% · control person
- ChangedFLEMING, KATE, MARIE · title PRESIDENT & DIRECTOR → PRESIDENT, DIRECTOR & TREASURER
- No longer listedPAVLICK, RANDY, MICHAEL · CHIEF COMPLIANCE OFFICER · Less than 5% · listed since Mar 2014
- AddedCONMEY, MICHAEL, JORDAN · CHIEF COMPLIANCE OFFICER · Less than 5%
- No longer listedBAUER, CHRIS, MICHAEL · INDEPENDENT DIRECTOR · Less than 5% · control person · listed since Nov 2001
- No longer listedBENTLEY, JOHN, EMERSON · CHAIRMAN OF THE BOARD · Less than 5% · control person · listed since Feb 2016
- Listed againJOELSON, RONALD, PETER · CHAIRMAN OF THE BOARD · Less than 5% · control person
- ChangedFLEMING, KATE, MARIE · title PRESIDENT → PRESIDENT & DIRECTOR
Older changes (7 more filings)
- No longer listedELLS, RALPH, DAVID · CHAIRMAN OF THE BOARD · Less than 5% · control person · listed since Jan 2015
- AddedBENTLEY, JOHN, EMERSON · CHAIRMAN OF THE BOARD · Less than 5% · control person
- No longer listedGE ANTERES CAPITAL CORP · MEMBER, QUINTEN ROAD MANAGEMENT LLC · 50–75% · control person · listed since Dec 2006
- No longer listedGENERAL ELECTRIC COMPANY · GE ANTERES CAPITAL CORP. · 75% or more · control person · listed since Oct 2005
- No longer listedJOELSON, RONALD, PETER · CHAIRMAN OF THE BOARD, PRESIDENT · Less than 5% · control person · listed since Aug 2012
- No longer listedMASON STREET ADVISORS, LLC · MEMBER AND MANAGER, QUINTEN ROAD MANAGEMENT LLC · 50–75% · control person · listed since Oct 2013
- No longer listedSWAIN, CHRISTOPHER, PAUL · VICE PRESIDENT-INVESTMENTS · Less than 5% · control person · listed since Mar 2013
- AddedELLS, RALPH, DAVID · CHAIRMAN OF THE BOARD · Less than 5% · control person
- AddedHEISTAD, ANDREW, JOHN · VICE PRESIDENT AND TREASURER · Less than 5%
- ChangedFLEMING, KATE, MARIE · title TREASURER, VICE PRESIDENT-OPERATIONS AND DIRECTOR → PRESIDENT
- ChangedPAVLICK, RANDY, MICHAEL · no longer a control person
- No longer listedDEANGELIS, JEFFERSON, VINCENT · PRESIDENT AND DIRECTOR · Less than 5% · control person · listed since Dec 2001
- No longer listedZIELINSKI, MICHAEL, W · CHIEF COMPLIANCE OFFICER · Less than 5% · control person · listed since Jan 2006
- AddedPAVLICK, RANDY, MICHAEL · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
- ChangedFLEMING, KATE, MARIE · title TREASURER AND VICE PRESIDENT-OPERATIONS → TREASURER, VICE PRESIDENT-OPERATIONS AND DIRECTOR
- ChangedJOELSON, RONALD, PETER · title CHAIRMAN OF THE BOARD → CHAIRMAN OF THE BOARD, PRESIDENT
- AddedGE ANTERES CAPITAL CORP · MEMBER, QUINTEN ROAD MANAGEMENT LLC · 50–75% · control person
- AddedGENERAL ELECTRIC COMPANY · GE ANTERES CAPITAL CORP. · 75% or more · control person
- AddedMASON STREET ADVISORS, LLC · MEMBER AND MANAGER, QUINTEN ROAD MANAGEMENT LLC · 50–75% · control person
- AddedSWAIN, CHRISTOPHER, PAUL · VICE PRESIDENT-INVESTMENTS · Less than 5% · control person
- No longer listedDOLL, MARK, GEORGE · CHAIRMAN OF THE BOARD · Less than 5% · control person · listed since Nov 2001
- AddedJOELSON, RONALD, PETER · CHAIRMAN OF THE BOARD · Less than 5% · control person
- ListedBAUER, CHRIS, MICHAEL · INDEPENDENT DIRECTOR · Less than 5% · control person
- ListedDEANGELIS, JEFFERSON, VINCENT · PRESIDENT AND DIRECTOR · Less than 5% · control person
- ListedDOLL, MARK, GEORGE · CHAIRMAN OF THE BOARD · Less than 5% · control person
- ListedFLEMING, KATE, MARIE · TREASURER AND VICE PRESIDENT-OPERATIONS · Less than 5% · control person
- ListedTHE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY · PARENT COMPANY · 75% or more · control person
- ListedZIELINSKI, MICHAEL, W · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- ISHARES TR$16.4M +11.8%
- SPDR SERIES TRUST$16.0M +45.4%
- SCHWAB STRATEGIC TR$15.8M +44.7%
- SPDR SERIES TRUST$15.4M +24.1%
- INVESCO EXCHANGE TRADED FD T$10.0M +19.5%
MASON STREET ADVISORS, LLC Holdings (2026-06-30)
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | ISHARES TR | AGG | 464287226 | $302.0M | 27.21% | 3,050,830 | SH |
| 2 | ISHARES TR | IVV | 464287200 | $154.6M | 13.93% | 206,485 | SH |
| 3 | SPDR SERIES TRUST | SPTL | 78464A664 | $105.1M | 9.47% | 4,005,960 | SH |
| 4 | SPDR SERIES TRUST | SPMD | 78464A847 | $95.9M | 8.64% | 1,419,072 | SH |
| 5 | SPDR SERIES TRUST | SPSM | 78468R853 | $79.5M | 7.17% | 1,379,248 | SH |
| 6 | INVESCO EXCHANGE TRADED FD T | RSP | 46137V357 | $61.4M | 5.53% | 288,645 | SH |
| 7 | ISHARES TR | IEFA | 46432F842 | $61.3M | 5.52% | 634,753 | SH |
| 8 | SPDR SERIES TRUST | RWR | 78464A607 | $51.2M | 4.61% | 453,255 | SH |
| 9 | SCHWAB STRATEGIC TR | SCHH | 808524847 | $51.2M | 4.61% | 2,161,115 | SH |
| 10 | AMERICAN CENTY ETF TR | AVLV | 025072349 | $43.3M | 3.90% | 474,820 | SH |
| 11 | ISHARES TR | IQLT | 46434V456 | $39.3M | 3.54% | 792,666 | SH |
| 12 | J P MORGAN EXCHANGE TRADED F | JPST | 46641Q837 | $25.0M | 2.25% | 494,716 | SH |
| 13 | DIMENSIONAL ETF TRUST | DFIV | 25434V807 | $22.4M | 2.02% | 414,285 | SH |
| 14 | ABRDN ETFS | BCI | 003261104 | $12.1M | 1.09% | 540,495 | SH |
| 15 | ISHARES INC | IEMG | 46434G103 | $5.6M | 0.51% | 68,080 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-12 | $1.11B | 15 | 0001167711-26-000005 |
| 2026-03-31 | 2026-05-07 | $1.02B | 15 | 0001167711-26-000004 |
| 2025-12-31 | 2026-02-04 | $1.02B | 15 | 0001167711-26-000001 |
MILWAUKEE, WI 53202