Inflation Protection Portfolio
Data updated: 2026-08-20
C000050276 — Inflation Protection Portfolio. Long Treasury / Sovereign Bond · $424.38M AUM · 0.46% expense ratio. Holdings, fees, performance and SEC filings.
C000050276 Fund Overview
Inflation Protection Portfolio is a US mutual fund managed by Northwestern Mutual Series Fund INC, categorised as Long Treasury / Sovereign Bond. ABC INVEST provides holdings, performance, costs, cashflows, risk data, prospectus documents and SEC filings, sourced from SEC filings.
- Type: US mutual fund
- Manager: Northwestern Mutual Series Fund INC
- Category: Long Treasury / Sovereign Bond
- Assets under management: $424.38M
- 1-year return: 3.6%
- SEC CIK: 0000742212
- SEC series ID: S000018228
- Share class ID: C000050276
C000050276 Investment Objective and Strategy
Inflation Protection Portfolio describes its objective and strategy as follows, from its latest prospectus filed with the SEC by Northwestern Mutual Series Fund INC.
Investment objective
The investment objective of the Portfolio is to pursue total return using a strategy that seeks to protect against U.S. inflation.
Principal investment strategy
The Portfolio invests substantially all of its assets in investment-grade debt securities. To help protect against U.S. inflation (as measured by the change in the Consumer Price Index over time), under normal conditions, the Portfolio will invest over 50% of its net assets (plus any borrowings for investment purposes) in inflation-indexed debt securities. These securities include inflation-indexed U.S. Treasury Securities, inflation-indexed securities issued by U.S. government agencies and instrumentalities other than the U.S. Treasury, and inflation-indexed securities issued by domestic and foreign corporations and governments, and may include those located in emerging markets. Inflation-indexed securities are designed to protect the future purchasing power of the money invested in them.
The Portfolio also may invest in fixed income securities that are not inflation-indexed. Such investments may include other investment grade debt securities, including collateralized mortgage obligations, mortgage-backed securities, including commercial mortgage-backed securities and agency mortgage-backed securities, and asset-backed securities, including collateralized loan obligations, whether issued by the U.S. government, its agencies or instrumentalities, corporations or other non-governmental issuers, or foreign governments. Investment grade securities are generally securities rated investment grade by major credit rating agencies (BBB- or higher by S&P; Baa3 or higher by Moodys; BBB- or higher by Fitch) or, if unrated, determined by the Portfolios adviser to be of comparable quality.
Due to Internal Revenue Code provisions and regulations governing insurance product funds, no more than 55% of the Portfolios assets may be invested in securities issued by the same entity. Because the number of inflation-indexed debt securities issued by entities is limited, at times the Portfolio may have a substantial position in non-inflation-indexed securities. To seek to reduce the impact of this limitation, the adviser may purchase (long) inflation swap agreements to manage or reduce the risk of the effects of inflation with respect to the Portfolios position in non-inflation-indexed securities. The adviser is not limited to a specific weighted average maturity or duration range. However, the adviser monitors the Portfolios weighted average maturity and duration and seeks to adjust it as appropriate, taking into account market conditions, the current inflation rate and other relevant factors.
The Portfolio may invest up to 20% of its total assets in securities denominated in foreign currencies and may invest beyond this limit in U.S. dollar denominated securities of foreign issuers. The Portfolio may hedge some or all of its foreign currency by utilizing forward foreign currency exchange contracts to seek to reduce the risk of loss due to fluctuations in the currency exchange rates. The Portfolio may also use interest rate futures to adjust overall interest rate exposure when the adviser deems it to be advantageous. The Portfolio may sell a security for a variety of reasons, including its assessment of the securitys relative attractiveness in light of its evaluation of current economic conditions or the risk of inflation, or to manage the Portfolios maturity and credit quality standards.
C000050276 Holdings
Top 10 holdings of Inflation Protection Portfolio by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| United States Treasury | 8.53% |
| United States Treasury | 4.71% |
| United States Treasury | 4.61% |
| United States Treasury | 4.61% |
| United States Treasury | 3.10% |
| United States Treasury | 2.71% |
| United States Treasury | 2.32% |
| United States Treasury | 2.14% |
| United States Treasury | 2.07% |
| United States Treasury | 1.70% |
C000050276 Portfolio Allocation
Asset-class allocation of Inflation Protection Portfolio by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 70.3% |
| Securitized | 26.6% |
| Cash & Equivalents | 1.8% |
| Derivatives | 1.8% |
C000050276 Performance
Total returns for C000050276 (as of 2026-10-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 1.4% |
| 1 year | 3.6% |
| 3 years (annualised) | 3.8% |
| 5 years (annualised) | 0.8% |
C000050276 Risk Information
Risk metrics for C000050276, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 2.9%
C000050276 Costs and Fees
C000050276 costs about $46 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.46%
- Gross expense ratio: 0.59%
- Portfolio turnover: 42%
- Brokerage commissions: 0.07 bps of average net assets (SEC N-CEN)
C000050276 Cashflows
Over the 12 months to 2026-06, Inflation Protection Portfolio had net inflows of $12.95M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-06 | $378.20K |
| 2026-05 | $2.00M |
| 2026-04 | −$2.49M |
| 2026-03 | −$1.27M |
| 2026-02 | −$43.58K |
| 2026-01 | $324.66K |
C000050276 Debt Constituents
Largest debt holdings of Inflation Protection Portfolio by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| United States Treasury | 8.53% |
| United States Treasury | 4.71% |
| United States Treasury | 4.61% |
| United States Treasury | 4.61% |
| United States Treasury | 3.10% |
| United States Treasury | 2.71% |
| United States Treasury | 2.32% |
| United States Treasury | 2.14% |
| United States Treasury | 2.07% |
| United States Treasury | 1.70% |
C000050276 Prospectus and SEC Filings
Official Inflation Protection Portfolio filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
- Prospectus (485BPOS) — filed 2026-04-24
- Prospectus (485BPOS) — filed 2025-04-25
- Prospectus supplement (497) — filed 2024-04-30
- Portfolio holdings (N-PORT) — filed 2026-08-20
- Portfolio holdings (N-PORT) — filed 2026-05-27
- Portfolio holdings (N-PORT) — filed 2026-02-23
- Annual census (N-CEN) — filed 2026-03-12
- Annual census (N-CEN) — filed 2025-03-11
Related Funds
Other Long Treasury / Sovereign Bond funds tracked on ABC INVEST:
Data Sources
ABC INVEST compiles this page from public filings made to the U.S. Securities and Exchange Commission (SEC) through EDGAR: portfolio holdings and monthly cashflows from Form N-PORT, expenses and returns from fund prospectuses (Form 485BPOS) and the SEC DERA Risk/Return Summary data sets, annual data from Form N-CEN, and shareholder reports from Form N-CSR.