Mason Street Advisors, LLC holds a concentrated book of 15 stocks worth $1.1B as of Q2 2026 (disclosed Aug 12, 2026, a ~43-day 13F lag). This quarter they opened Avantis US Large Cap Value and trimmed Ishares Core S&P 500 ETF. Their largest long position is Ishares Core U.S. Aggregate at 27% of the equity book.
Top-heavy: concentrated book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
0% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
Other tracked managers holding the same core names as Mason Street Advisors, LLC
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| BANK OF AMERICA CORP /DE/ | 16 / 15 | $61.1B |
| MORGAN STANLEY | 16 / 15 | $47.8B |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO | 16 / 15 | $42.2B |
| ENVESTNET ASSET MANAGEMENT INC | 16 / 15 | $40.4B |
| JONES FINANCIAL COMPANIES LLLP | 16 / 15 | $36.3B |
| WELLS FARGO & COMPANY/MN | 16 / 15 | $35.9B |
| Creative Planning | 16 / 15 | $29.3B |
| JPMORGAN CHASE & CO | 16 / 15 | $26.9B |
Ranked by how many of Mason Street Advisors, LLC's top 15 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Ishares TR CORE US AGGBD ET | $302.0M | 3.05M | 27.2% | ▲+0.1% Added · +2K sh | |
| 2 | Ishares TR CORE S&P500 ETF | $154.6M | 206.5K | 13.9% | ▼−2.5% Reduced · −5K sh | |
| 3 | SPDR Series Trust ST LON TREAS ETF | $105.1M | 4.01M | 9.5% | ▲+0.2% Added · +7K sh | |
| 4 | SPDR Series Trust ST STR P400MID | $95.9M | 1.42M | 8.6% | ▼−9.1% Reduced · −143K sh | |
| 5 | SPDR Series Trust ST STR SP600 SML | $79.5M | 1.38M | 7.2% | ▲+4.0% Added · +53K sh | |
| 6 | Invesco Exchange Traded FD T S&P500 EQL WGT | $61.4M | 288.6K | 5.5% | ▲+7.8% Added · +21K sh | |
| 7 | Ishares TR CORE MSCI EAFE | $61.3M | 634.8K | 5.5% | ▼−11% Reduced · −76K sh | |
| 8 | SPDR Series Trust ST STR DOW REIT | $51.2M | 453.3K | 4.6% | ▲+30% Added · +105K sh | |
| 9 | Schwab Strategic TR US REIT ETF | $51.2M | 2.16M | 4.6% | ▲+31% Added · +515K sh | |
| 10 | American Centy ETF TR US LARGE CAP VLU | $43.3M | 474.8K | 3.9% | ▲New New position | |
| 11 | Ishares TR MSCI INTL QUALTY | $39.3M | 792.7K | 3.5% | ▲+3.1% Added · +24K sh | |
| 12 | J P Morgan Exchange Traded F ULTRA SHRT ETF | $25.0M | 494.7K | 2.3% | ▲+1.7% Added · +8K sh | |
| 13 | Dimensional ETF Trust INTERNATNAL VAL | $22.4M | 414.3K | 2.0% | ▲+2.7% Added · +11K sh | |
| 14 | Abrdn Etfs BBRG ALL COMD K1 | $12.1M | 540.5K | 1.1% | ▲+52% Added · +184K sh | |
| 15 | Ishares Inc CORE MSCI EMKT | $5.6M | 68.1K | 0.5% | ▲+56% Added · +25K sh |
The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1167711/holdings"
Use Arkolith to show MASON STREET ADVISORS, LLC's latest holdings, largest changes, and filing provenance.
As-of date vs the date the SEC received each filing
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.