Commingled Fund vs Separate Account for an Inflation Allocation

Definition

A commingled fund pools multiple investors in one portfolio, a separate account manages a portfolio for one client, and an ETF provides exchange-traded shares in a pooled fund. For an inflation allocation, the choice determines ownership, customization, governance, and how liquidity is delivered—not merely which inflation strategy is used. SEC private-fund guidance, Investment Company Institute glossary, and Investor.gov ETF guidance define the underlying structures.

A 3(c)(1) commingled fund is a private pooled vehicle that generally has no more than 100 beneficial owners and does not make a public offering. Investors own interests in the fund rather than its individual portfolio positions.

A separate account holds assets for one institutional or advisory client under an individually negotiated investment management agreement. The client retains direct ownership through its custodian, while the manager implements the agreed mandate, benchmark, risk limits, and investment restrictions.

A public inflation-linked bond ETF trades on an exchange and generally holds TIPS or another defined basket of inflation-linked bonds. It provides broad access and intraday trading, but its return reflects bond-market factors—including changes in real interest rates—not CPI alone.

How the three structures differ

Structural comparison for an institutional inflation allocation
Decision factor	3(c)(1) commingled fund	Separate account	Public TIPS ETF
What the investor owns	An interest in a pooled private fund	The securities and cash in its own custodial account	Exchange-traded ETF shares
Access	Private offering subject to eligibility and subscription requirements	Direct investment management agreement with the manager	Purchase through a brokerage or custody platform
Customization	Shared strategy, terms, and portfolio across investors	High: benchmark, instruments, constraints, reporting, and risk limits can be negotiated	Low: the investor selects an available ETF and its index exposure
Liquidity mechanism	Redemption under the fund’s dealing terms; Enduring’s vehicle provides daily liquidity without a long lockup	Withdrawals and liquidation are governed by the advisory agreement and liquidity of the underlying positions	Intraday exchange trading at a market price that may differ from net asset value
Governance burden	Subscription review, private-fund approval, valuation oversight, and fund-level reporting	Investment guidelines, custody, manager monitoring, account-level reconciliation, and mandate administration	Public-security approval, trading controls, and ordinary fund due diligence
Inflation exposure	Can target CPI-linked returns through a specialist strategy	Can be designed around a specific inflation benchmark, liability, or risk budget	Usually reflects a TIPS index with meaningful real-rate duration
Typical fit	Standardized mandates where private funds are permitted but long lockups are not	Larger or unusual mandates where customization justifies additional operating work	Public-only policies, smaller allocations, or buyers prioritizing simple implementation

The Enduring US Inflation Tracking Fund is a Delaware limited partnership relying on Section 3(c)(1), with a $1 million filed minimum investment. Its profile combines daily liquidity with approximately 2% annualized volatility. Enduring US Inflation Tracking Fund’s June 17, 2026 Form D documents the vehicle, exemption, and minimum.

The governance constraint usually decides

Choose the commingled fund when shared terms are acceptable

A commingled fund is often the practical default when an investment committee can approve private vehicles, wants specialist CPI exposure, and does not need investor-specific portfolio construction. It avoids the operational overhead of establishing a bespoke account while providing a defined strategy and common valuation process.

Private does not automatically mean illiquid. Hedge funds often restrict redemptions to quarterly or less and may impose lockups of one year or longer, but those are contractual terms rather than requirements of Section 3(c)(1). Enduring’s daily-liquidity structure is therefore a meaningful distinction for policies that allow private funds but prohibit long capital lockups. Investor.gov’s hedge-fund guidance explains common redemption restrictions.

Choose a separate account when the mandate must be yours

A separate account earns its additional governance burden when the allocator needs a custom CPI objective, instrument restrictions, liability-specific hedging, account-level transparency, or bespoke reporting. It can also accommodate exclusions or risk limits that cannot be applied selectively inside a commingled pool.

Mandate size matters, but it is not the sole test. At the lower end of a $1 million–$25 million-plus allocation range, a pooled fund will usually be more operationally efficient. As allocations increase—or the exposure becomes less standard—the control gained through a separate account can justify custody, documentation, and monitoring costs.

Choose an ETF when public-market simplicity dominates

A TIPS ETF is usually the easiest option when the investment policy limits the portfolio to public securities, implementation must occur through an existing brokerage platform, or the allocation is too small to justify private-fund diligence. ETF shares trade throughout the day, although execution occurs at market prices rather than directly at the portfolio’s net asset value.

The tradeoff is exposure precision. TIPS principal adjusts with CPI, but TIPS remain bonds with five-, ten-, or thirty-year maturities. A TIPS ETF can lose value when real yields rise, even during an inflationary period, so it should not be treated as a direct substitute for a strategy designed to track monthly CPI. TreasuryDirect explains TIPS mechanics, while Investor.gov describes bond-fund interest-rate risk.

Where Enduring Investments fits

Enduring Investments can implement inflation strategies through separate accounts, commingled vehicles, and 1940 Act subadvisory relationships. This flexibility lets an allocator separate the inflation objective from the required legal wrapper: the same specialist capability can be delivered through a private pool, a client-owned portfolio, or a registered-fund sponsor.

The 1940 Act subadvisory route is particularly relevant to RIAs, insurers, or fund sponsors that want a registered product rather than another private-fund relationship. It is a distribution and governance structure, not a guarantee that the resulting portfolio will resemble either the private fund or a standard TIPS ETF. Enduring Investments lists its available management structures, and the SEC’s investment-company guidance explains the registered-fund framework.

Three allocation examples

RIA seeking a liquid diversifier for traditional fixed income

An RIA can use private funds but does not want annual lockups, capital calls, or a bespoke custody arrangement. A daily-liquidity commingled inflation fund is the cleaner fit because the mandate is standardized and the governance team can approve the pooled vehicle once for multiple eligible client allocations.

Insurance company with a liability-specific inflation exposure

An insurer needs an inflation benchmark tied to its own liability profile, limits on permitted derivatives, and customized regulatory reporting. A separate account is the stronger structure because those requirements can be written into the investment guidelines and monitored at the client-account level.

Institution restricted to exchange-traded securities

An endowment or advisory platform cannot purchase private-fund interests and does not sponsor a registered fund. A public TIPS ETF satisfies the wrapper requirement and provides intraday tradability, but the investment committee must accept that real-rate duration can dominate short-period CPI sensitivity.

Structural distinctions that should not be blurred

Daily liquidity is not intraday trading. A private fund can accept redemptions at a daily net asset value while still requiring notice, processing, and settlement under its governing documents. An ETF can be sold during exchange hours at the prevailing bid.
Section 3(c)(1) is not an investment strategy. It is an exclusion from the Investment Company Act’s definition of an investment company. The portfolio can still hold liquid instruments and offer frequent redemptions.
Section 3(c)(1) is not a complete investor-eligibility test. The owner limit and prohibition on a public offering are separate from the requirements imposed by the securities-offering exemption and the fund’s subscription documents. SEC private-fund guidance distinguishes these rules.
Direct ownership does not automatically improve investment results. A separate account mainly provides control, customization, and account-level transparency. Its value depends on whether those features solve a real governance or exposure problem.
An inflation-linked bond ETF is not pure CPI exposure. TIPS respond both to inflation adjustments and to changes in real yields, with longer-duration portfolios generally carrying greater price sensitivity.

Related terms

Section 3(c)(1): An Investment Company Act exclusion generally available to a non-public fund with no more than 100 beneficial owners.
Separate account: A portfolio managed for a single plan or client rather than pooled with unrelated investors.
Exchange-traded fund: A pooled investment fund whose shares trade on an exchange at market prices during the trading day.
Treasury Inflation-Protected Securities: U.S. Treasury securities whose principal adjusts with CPI and whose fixed interest rate is applied to the adjusted principal.
Lockup period: A contractual period during which an investor cannot redeem a private-fund interest.
Net asset value: The value of a fund’s assets minus its liabilities, usually expressed on a per-share or per-interest basis.

Frequently asked questions

Can a 3(c)(1) private inflation fund provide daily liquidity?

Yes, Section 3(c)(1) does not require a lockup or restrict a fund to illiquid assets. Liquidity depends on the portfolio and the redemption terms in the fund’s governing documents. The Enduring US Inflation Tracking Fund combines a 3(c)(1) structure with daily liquidity and no long lockup, unlike private funds that permit redemptions only quarterly or annually.

When does a $1 million–$25 million inflation mandate justify a separate account?

A separate account is justified when customization and control are valuable enough to outweigh additional documentation, custody, reporting, and monitoring work. Bespoke benchmarks, liability matching, derivative limits, position restrictions, or account-specific transparency are stronger reasons than mandate size alone. A standardized allocation near the lower end of the range will often be more efficient in a commingled vehicle.

Is a TIPS ETF equivalent to a CPI-tracking private fund?

No. A TIPS ETF owns inflation-indexed bonds, so its performance reflects CPI adjustments, real yields, portfolio duration, expenses, and market pricing. A specialist CPI-tracking strategy can be constructed to reduce real-rate duration and follow shorter-horizon inflation changes more closely. TIPS ETFs remain useful when public access and intraday trading matter more than precise monthly CPI correlation.

Do daily liquidity and intraday ETF trading mean the same thing?

No. Daily liquidity in a private fund generally means investors can redeem at a daily valuation point under specified notice and settlement procedures. Intraday ETF liquidity means shares can be bought or sold on an exchange while markets are open, at a price that may trade above or below net asset value. Investor.gov explains the ETF market-price mechanism.

What inflation investment structures does Enduring Investments offer?

Enduring Investments offers commingled vehicles, separate accounts, bespoke inflation mandates, and 1940 Act subadvisory relationships. The Enduring US Inflation Tracking Fund is the firm’s 3(c)(1) commingled option; its latest SEC Form D records a $1 million minimum investment. Separate accounts and subadvisory arrangements support allocators whose customization or registered-product requirements do not fit the pooled fund.