Mason Street Advisors, LLC
In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 7, 2026), Mason Street Advisors, LLC reported 15 stock positions worth $1.0 billion. Its top holding was iShares Core U.S. Aggregate (AGG) at 29.6% of the portfolio, followed by iShares Core S&P 500 ETF (IVV, 13.5%) and SS SPDR PF LNG TRM TSY E-Usd (SPTL, 10.3%). Compared with Q4 2025, it opened 2 new positions, sold out of 2, added to 9 and reduced 4. The biggest buy was iShares Core MSCI Eafe ETF (IEFA, shares +12374%) and the biggest sale an exit from iShares Core S&P Small-Cap E (IJR).
- Most Recent 13F
- Q2 2026
- Location
- MILWAUKEE, WI
- CIK
- 0001167711
- Portfolio Value
- $1.0B (Q1 2026)
- SEC Filing
- 0001167711-26-000004 ↗ filed May 7, 2026
Holdings Value
Holdings 15 stocks · $1.0B
| AGG iShares Core U.S. Aggregate | 29.58% | 3,049,263 | $302.7M | Reduce -1.9% |
| IVV iShares Core S&P 500 ETF | 13.51% | 211,681 | $138.3M | Add +0.4% |
| SPTL SS SPDR PF LNG TRM TSY E-Usd | 10.28% | 3,998,720 | $105.2M | Add +0.0% |
| SPMD SS SPDR P S&P 400 Midcap ETF | 9.04% | 1,561,969 | $92.5M | Reduce -1.6% |
| IEFA iShares Core MSCI Eafe ETF | 6.29% | 710,997 | $64.4M | Add +12373.6% |
| SPSM SS SPDR P S&P 600 Small Cap | 6.26% | 1,326,423 | $64.1M | Add +2.5% |
| RSP Invesco S&P 500 Equal Weight | 5.02% | 267,820 | $51.4M | Add +3.2% |
| VLUE iShares MSCI USA Value Facto | 4.00% | 288,200 | $41.0M | New |
| IQLT iShares MSCI International Q | 3.47% | 768,930 | $35.5M | Add +2.8% |
| SCHH Schwab US REIT ETF | 3.46% | 1,646,125 | $35.4M | Reduce -3.9% |
| RWR SS SPDR Dow Jones REIT ETF | 3.44% | 348,675 | $35.2M | Reduce -4.9% |
| JPST JPMorgan Ultra-Short Income | 2.41% | 486,336 | $24.6M | Add +1.2% |
| DFIV Dimensional International Va | 2.08% | 403,315 | $21.3M | Add +2.5% |
| BCI Abrdn Bloomberg All Commodit filed as ABRDN ETFS | 0.85% | 356,335 | $8.7M | Add +5.5% |
| IEMG iShares Core MSCI Emerging | 0.30% | 43,520 | $3.0M | New |
Portfolio Sells Q4 2025 → Q1 2026
| IJR iShares Core S&P Small-Cap E | Sold out | 0.00% | −5.62 |
| IJH iShares Core S&P Midcap ETF | Sold out | 0.00% | −3.90 |
| AGG iShares Core U.S. Aggregate | Reduce -1.9% | 29.58% | −0.95 |
| RWR SS SPDR Dow Jones REIT ETF | Reduce -4.9% | 3.44% | −0.10 |
| SCHH Schwab US REIT ETF | Reduce -3.9% | 3.46% | −0.06 |
| SPMD SS SPDR P S&P 400 Midcap ETF | Reduce -1.6% | 9.04% | −0.00 |
Portfolio Buys Q4 2025 → Q1 2026
| IEFA iShares Core MSCI Eafe ETF | Add +12373.6% | 6.29% | +6.25 |
| VLUE iShares MSCI USA Value Facto | New | 4.00% | +4.00 |
| SPSM SS SPDR P S&P 600 Small Cap | Add +2.5% | 6.26% | +0.30 |
| IEMG iShares Core MSCI Emerging | New | 0.30% | +0.30 |
| BCI Abrdn Bloomberg All Commodit | Add +5.5% | 0.85% | +0.20 |
| DFIV Dimensional International Va | Add +2.5% | 2.08% | +0.15 |
| RSP Invesco S&P 500 Equal Weight | Add +3.2% | 5.02% | +0.13 |
| IQLT iShares MSCI International Q | Add +2.8% | 3.47% | +0.13 |
| JPST JPMorgan Ultra-Short Income | Add +1.2% | 2.41% | +0.01 |
| SPTL SS SPDR PF LNG TRM TSY E-Usd | Add +0.0% | 10.28% | −0.13 |
| IVV iShares Core S&P 500 ETF | Add +0.4% | 13.51% | −0.69 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 15 | $1.1B | AGG, IVV, SPTL, SPMD, SPSM |
| Q1 2026 | 15 | $1.0B | AGG, IVV, SPTL, SPMD, IEFA |
| Q4 2025 | 15 | $1.0B | AGG, IVV, SPTL, SPMD, SPSM |
| Q3 2025 | 15 | $964.8M | AGG, IVV, SPTL, SPMD, IEFA |
| Q2 2025 | 15 | $854.5M | AGG, IVV, SPTL, SPMD, IEFA |
| Q1 2025 | 13 | $786.1M | AGG, IVV, SPTL, IEFA, SPMD |
| Q4 2024 | 12 | $772.6M | AGG, IVV, SPTL, IEFA, SPMD |
| Q3 2024 | 12 | $823.5M | AGG, IVV, SPTL, IEFA, SPMD |
| Q2 2024 | 12 | $743.0M | AGG, IVV, SPTL, IEFA, SCHH |
| Q1 2024 | 8 | $594.2M | IVV, AGG, IEFA, JPST, MINT |