Anti-Dilution Levies and Swing Pricing in Hedge Funds: Who Pays the Cost of Investor Flows

The anti-dilution levy hedge fund boards adopt is a charge paid to the fund by a subscribing or redeeming investor to cover the dealing costs that investor's transaction creates. Without it, the bid-offer spread, market impact, commissions, transaction taxes and FX conversion incurred in trading the portfolio fall on the investors who stay. The same cost can be placed inside the price through swing pricing, or through the older dual pricing model. The international reference point is the IOSCO Revised Recommendations for Liquidity Risk Management of May 2025, which ask responsible entities to consider and use anti-dilution tools so that investors bear the cost of their own liquidity. None of that is a Cayman requirement. For a Cayman hedge fund the question is one of fair design, honest disclosure and a mechanism the administrator can run.

"Every hedge fund pays dealing costs when investors move. The only question is who carries them. In our experience the managers who settle this at launch, with a modest levy or a documented swing policy sitting inside the NAV calculation policy, rarely have to defend the point later. Those who leave it silent discover the cost in the first large redemption, when continuing investors ask why their NAV fell by more than the market did. We treat anti-dilution design as part of the dealing terms, not as a footnote to them." David Lloyd, Chief Executive Officer at CV5 Capital

Executive Summary

Dealing costs are incurred by the fund, and someone pays them. The anti-dilution toolkit places that cost with the investor whose transaction caused it.

• An anti-dilution levy is paid to the fund, never to the manager, and leaves the published NAV untouched.
• Swing pricing adjusts the NAV per share on dealing days when net flows exceed a threshold, so the price itself carries the cost.
• The swing factor or levy rate should reflect explicit and implicit costs, including market impact, and should be back-tested.
• The IOSCO, FSB, EU, UK and Luxembourg positions are reference points for open-ended funds; the Cayman framework works through the offering document, the NAV calculation policy and the board.
• Swing pricing complicates performance reporting and performance fee calculations in ways a levy does not, which is why many hedge funds prefer the levy.

What Dilution Is and Why It Matters More Than It Looks

A fund's NAV is struck at mid or last-traded prices. When an investor redeems, the manager sells assets to raise cash and the fund realises less than the marked value. The shortfall is the spread, the market impact of the order, commissions, any transaction tax and the cost of converting proceeds into the dealing currency. When an investor subscribes, the mirror image applies as the cash is deployed. Those costs are booked by the fund and shared across all investors, while the transacting investor dealt at an undiluted price: that is dilution.

A cost of 30 to 50 basis points on the traded slice, applied to a redemption of a few per cent of NAV, moves the continuing NAV by only a few basis points. Over a year of flows the drag becomes visible in the track record. The second effect is behavioural. If early redeemers exit at an undiluted price while later redeemers absorb the cost, there is an incentive to leave first. That first-mover dynamic is why the international policy work on the liquidity mismatch problem in open-ended funds treats anti-dilution tools as structural rather than cosmetic. The exposure depends on the strategy: liquid equities carry impact on concentrated positions, credit carries wide spreads, and digital assets carry venue fees, on-chain gas and stablecoin conversion. The design question is the same in every case: what does it cost to trade a pro-rata slice of this portfolio, and who should bear it?

The Toolkit: Levy, Swing Pricing and Dual Pricing

The IOSCO implementation guidance of May 2025 identifies five anti-dilution tools: swing pricing, valuation at bid or ask prices, dual pricing, the anti-dilution levy and fixed subscription or redemption fees. Directive (EU) 2024/927 has written harmonised definitions into the AIFMD framework. Under it an anti-dilution levy is a fee paid to the fund by an investor on subscription or redemption, compensating the fund for the cost of liquidity incurred because of the size of that transaction. Swing pricing is a pre-determined mechanism by which the NAV per share is adjusted by a factor reflecting the cost of liquidity. The economic aim is identical; the difference lies in where the adjustment sits and what it does to the reported number.

Two features of the levy explain why hedge funds often favour it. It is visible to the transacting investor as a line on the contract note rather than buried in the price. And because the NAV is not swung, the track record, the high-water mark and any series or equalisation calculation proceed on an undisturbed number.

Swing Pricing in Detail: Full, Partial and the Threshold

Swing pricing moves the price rather than adding a charge. On a dealing day with net redemptions the NAV per share is reduced by the swing factor, so every redeemer receives a price that carries the estimated cost of raising the cash. On a day with net subscriptions the NAV is increased, so subscribers pay the cost of deployment.

Full swing pricing applies the factor on every dealing day, in whichever direction net flow runs. Partial swing pricing applies it only when net flows exceed a swing threshold expressed as a percentage of NAV. The IOSCO guidance states that any threshold should be appropriate and sufficiently prudent so as not to result in any material dilution impact, and that thresholds for funds holding less liquid assets should be set more prudently.

A worked example

The figures below are illustrative and hypothetical. They show one dealing day for a monthly-dealt fund with an unswung NAV of US$100 million and 100,000 shares in issue. The fund operates a partial swing with a 3 per cent threshold. The swing factor of 40 basis points is the manager's estimate of the cost of liquidating a pro-rata slice of the book.

Both tools protect the continuing investor by the same amount. The swing publishes a NAV 40 basis points below the fund's economic value on that day, which flows into any performance series struck from published NAVs. The levy leaves the published NAV at economic value and collects the cost as a separate credit.

Estimating and Reviewing the Swing Factor or Levy Rate

The IOSCO guidance describes the cost of liquidity as the sum of explicit and implicit transaction costs. Explicit costs are brokerage, trading levies, taxes and settlement fees, generally quantifiable in advance. Implicit costs are the bid-ask spread and market impact, which are estimated using best efforts from analysis of previous transactions. Significant market impact should be included. The starting point is the cost of transacting a pro-rata slice of all assets in the portfolio, adjusted where professional judgement indicates the fund would trade differently.

In practice the manager's trading and risk functions produce the estimate and the administrator applies it. A typical approach records realised spread and impact by asset class from the fund's own executions, adds the explicit components, and weights the result by the pro-rata portfolio. The output is a factor for normal conditions and a higher factor for stress, both within a disclosed maximum. The stressed factor should match the cost assumptions in the fund's liquidity stress testing framework.

Review is where most frameworks are thin. The 2025 IOSCO implementation guidance describes back-testing the market impact model over time to improve its accuracy. The December 2023 guidance it consolidates described ex-ante review, so the factor responds to market changes, and ex-post review comparing the factor applied with the dealing prices achieved. The Luxembourg regulator's FAQ on swing pricing, version 5 of 8 January 2025, expects a board-approved policy setting out the methodology for determining and periodically reviewing the factors and thresholds, a sensible template even where the FAQ does not apply.

The pricing committee and the board

The December 2023 IOSCO guidance described a governance committee bringing together pricing, risk and administration functions, with documented decisions and periodic reporting to the board. For a platform hedge fund the practical shape is a pricing committee that meets ahead of each dealing day with confirmed flows, reviews the proposed factor, records any departure and reports to the directors. The directors approve the policy, the maximum factor and the threshold, and receive the ex-post comparison; they do not set the factor day by day.

Disclosure, the Offering Document and the Cayman Framework

Cayman law does not prescribe an anti-dilution tool; what it requires is disclosure. Section 4(6) of the Mutual Funds Act (2025 Revision) provides that an offering document shall describe the equity interests in all material respects. It must also contain such other information as is necessary to enable a prospective investor to make an informed decision. A levy or swing mechanism changes the price at which an investor deals, which is a material term. Where a mechanism is added to an existing fund, section 4(8) applies: a promoter or operator aware of a change materially affecting the filed offering document must file the amendment with CIMA within twenty-one days.

The second Cayman instrument is regulatory: CIMA's Rule on Calculation of Asset Values for Regulated Mutual Funds, issued in July 2020, requires a fund to establish, implement and maintain a NAV calculation policy. The policy must ensure the NAV is fair, complete, neutral, free from material error and verifiable, must be written and disclosed in the offering document, and must be approved and reviewed by the operators at least annually. A swing mechanism alters the NAV per share and belongs inside that policy. Most funds document a levy in the same place. The wider NAV process is covered in CV5's guide to valuation, NAV production and investor reporting.

What the document should say follows from the international guidance rather than from statute. IOSCO asks for disclosure of which tools may be applied and on what basis, the purpose of protecting continuing investors, and the constituents of the cost and how it is estimated. It also expects a mechanism allowing an adjustment beyond any disclosed range where necessary in stress. The 2023 guidance noted the tension between transparency and gaming: publishing the exact threshold and factor lets a large investor size a redemption just under the line, so ranges and delayed ex-post disclosure are often preferred.

Performance Reporting, Performance Fees, Gates and Side Pockets

Swing pricing changes the published NAV that the track record is built from. A swing on a month-end dealing day depresses or inflates that month's return by the factor, and the reversal appears the following month. The effect nets out over time, but it adds volatility to the series and can trip drawdown or hurdle tests. Many funds that swing therefore report performance on the unswung NAV. A levy avoids the problem because the NAV is never adjusted.

Performance fees raise the same issue in sharper form. If the accrual is computed on a swung NAV, the manager is paid on a number moved by flow rather than by performance. The Luxembourg FAQ recommends that any performance fee be charged on the unswung NAV, and that is the sensible default anywhere. For funds using series accounting or equalisation, crystallisation on redemption, the high-water mark of each series and the equalisation credit all need a stated basis. The mechanics are set out in CV5's explanation of equalisation, series accounting and performance fee fairness.

The interaction with gates and side pockets is one of sequence: a gate limits how much can be redeemed on a dealing day, and an anti-dilution tool prices the redemption actually processed. In stress both may operate together, the gate controlling quantity and the stressed rate controlling cost. A side pocket removes illiquid assets from the dealing NAV, so the rate should be estimated on the liquid portfolio that will actually be traded, not the whole book. CV5's guide to gates, side pockets and suspensions as liquidity tools covers the quantity side. The question of when a hedge fund can suspend redemptions sits beyond both, at the point where pricing is no longer possible.

What Is Proportionate for a Hedge Fund

The international work is written with daily-dealt funds in mind. The FSB and IOSCO categorisation keeps daily dealing for funds in liquid assets and allows it for funds in less liquid assets where anti-dilution tools are implemented. Funds with significant illiquid holdings are expected to deal less often or require longer notice or settlement. A hedge fund dealing monthly or quarterly with notice and a lock-up is already in that third group by design. It addresses liquidity mismatch through lock-ups, notice periods and redemption terms before any pricing tool is considered.

That changes the calculation. With a notice period the manager knows the net flow before the dealing day and can pre-position, spreading sales over days or weeks and reducing impact. The residual cost is smaller and more predictable than in a daily fund, which argues for a variable levy above a threshold rather than a full swing. The flows are also certain when the rate is set.

Proportionality runs the other way too. A concentrated strategy in small-cap equities, distressed credit or thinly traded tokens can face dealing costs of several per cent on a large redemption. For that fund a disclosed maximum levy in the low single digits, with a stressed rate at the directors' discretion, is the difference between a fair exit and a transfer of value to the investor leaving.

• Choose the tool for the flow pattern. A variable levy above a threshold suits most monthly hedge funds; partial swing suits larger funds with frequent material flows; full swing and dual pricing are seldom proportionate.
• State the maximum and the discretion. Disclose the maximum rate, who sets it, whether the directors may waive it, and whether a stressed rate applies in defined conditions.
• Send the proceeds to the fund. A levy retained by the manager is a fee, not an anti-dilution tool.
• Decide the performance basis. If swinging, state that performance and performance fees use the unswung NAV.

Common mistakes

• Describing a fixed subscription fee as anti-dilution when it is paid to the manager or a distributor.
• Setting a rate at launch and never revisiting it, so it reflects the market of three years ago.
• Applying the levy at the manager's discretion without a documented committee decision, which invites the question of whether it managed flows rather than costs.

Key Takeaways

• Decide the anti-dilution tool at launch, alongside dealing frequency, notice and gates, and write it into the offering document and the NAV calculation policy.
• For a monthly or quarterly hedge fund, default to a variable levy paid to the fund above a stated threshold with a disclosed maximum; adopt swing pricing only where flows are frequent and material.
• Build the rate from explicit costs plus spread and market impact on a pro-rata slice of the liquid book, and back-test it against realised execution annually.
• If swinging, calculate performance and performance fees on the unswung NAV and say so; give series or equalisation accounting a defined basis.
• Run the decision through a documented pricing committee reporting to the directors, who approve the policy, the maximum and the threshold.
• Treat the IOSCO, FSB, EU, UK, Luxembourg and US positions as reference points for design and disclosure, not as Cayman requirements.

Frequently Asked Questions

What is an anti-dilution levy in a hedge fund?

An anti-dilution levy is a charge applied to a subscription or redemption and paid to the fund, not to the manager. It is intended to cover the dealing costs the fund incurs in deploying or raising the cash for that transaction, so that continuing investors do not bear them. It is usually expressed as a percentage of the transaction, set within a disclosed maximum, and often applied only when net flows exceed a threshold.

How is swing pricing different from an anti-dilution levy?

Both move the cost of dealing to the transacting investor. A levy is a separate charge and leaves the NAV per share unchanged. Swing pricing adjusts the NAV per share itself, downwards on net redemption days and upwards on net subscription days, so the published price carries the cost. The economic protection for continuing investors is the same; the difference is in reporting, performance fee mechanics and operational complexity.

Is swing pricing required for a Cayman hedge fund?

No. Cayman law does not prescribe swing pricing, an anti-dilution levy or any other specific tool. The Mutual Funds Act requires the offering document to describe the equity interests in all material respects, and CIMA's Rule on Calculation of Asset Values requires a disclosed NAV calculation policy approved by the operators. Whether to adopt a tool, and which one, is a design decision for the fund and its directors.

How is the swing factor calculated?

The swing factor is an estimate of the cost of liquidity for a pro-rata slice of the portfolio. It combines explicit costs such as commissions, transaction taxes and settlement fees with implicit costs, meaning the bid-ask spread and the market impact of the trades. The estimate is typically produced by the manager's trading and risk functions, applied by the administrator, capped by a disclosed maximum and reviewed against realised execution costs.

Does swing pricing affect the performance fee?

It can, if the fee is calculated on the swung NAV, because the NAV has then been moved by investor flow rather than by performance. The common recommendation, including in the Luxembourg regulator's FAQ, is to charge the performance fee on the unswung NAV. Funds using series accounting or equalisation should state which NAV each calculation uses in the offering document.

What is the difference between a swing threshold and a swing factor?

The swing threshold is the level of net subscriptions or net redemptions, expressed as a percentage of NAV, at which the swing is applied. The swing factor is the percentage by which the NAV per share is adjusted once the threshold is crossed. Full swing pricing has no threshold and applies the factor on every dealing day; partial swing pricing applies it only above the threshold.