When a Singapore company raises a new round of funding at a lower valuation than the previous round, existing investors who paid a higher price per share can find their percentage ownership, and the value of their stake, quietly eroded. Anti-dilution provisions are the contractual mechanism that shareholders’ agreements use to guard against exactly this scenario. Yet while drag-along rights, tag-along rights and rights of first refusal are now well covered ground for Singapore founders and investors, the actual mechanics of anti-dilution protection, full ratchet versus broad-based weighted average, how the adjustment is calculated, and how it interacts with the Companies Act 1967, are rarely explained in plain terms.

This article sets out what anti-dilution provisions do, the two dominant drafting models used in Singapore shareholders’ agreements, worked examples of how each calculates a post-round conversion price, and the statutory and constitutional issues a corporate secretary or director should flag before a down round is implemented.

What anti-dilution provisions actually protect against

Anti-dilution provisions are not a general guarantee against dilution from ordinary fundraising. Every time a company issues new shares, existing shareholders are diluted in the arithmetic sense: their percentage of the enlarged share capital falls. That form of dilution is normal and expected, and no drafting convention protects against it (the closest tool is a pre-emption right, which lets an existing shareholder subscribe for new shares to maintain their percentage, a mechanism already covered in our guide to share issuances, allotments and pre-emption rights).

Anti-dilution provisions instead protect against value dilution in a down round: a subsequent issue of shares at a price per share lower than what an earlier investor paid. Without protection, an investor who bought preference shares at S$10.00 each in a Series A round has no recourse if the company later issues Series B shares at S$4.00 each, even though the lower price effectively marks down the value of the investor’s earlier stake. The anti-dilution clause responds by adjusting the conversion ratio or conversion price of the investor’s preference shares, so that on conversion to ordinary shares the investor receives more ordinary shares than the original 1:1 ratio would have given, partially or fully compensating for the value lost.

This is why anti-dilution provisions are almost always drafted into the rights attaching to preference shares, not as a free-standing shareholders’ agreement covenant. The mechanism operates through the conversion formula in the company’s constitution or the terms of issue of the preference shares, with the shareholders’ agreement setting out the commercial agreement that underlies it.

Full ratchet: the investor-favourable model

Under a full ratchet provision, if the company issues new shares at any price lower than the price the protected investor originally paid, the investor’s conversion price is reset downward to match the new, lower issue price, regardless of how many new shares are issued. A single share issued at a nominal price can trigger a full reset.

Consider it this way: an investor bought preference shares at S$10.00 each. A later round issues shares at S$4.00 each, even if that round involves only a small number of shares relative to the company’s total capital. Under full ratchet, the investor’s conversion price resets to S$4.00, meaning on conversion the investor receives two and a half ordinary shares for every preference share originally held.

Full ratchet is the most protective model for the investor and the most punitive for the founders and any other shareholders who do not benefit from the same protection, because the reset is triggered irrespective of the size of the dilutive issuance. It is now uncommon in Singapore venture deals outside distressed or highly investor-favourable rounds, precisely because of how severely it can concentrate ownership in the protected investor’s favour after a down round.

Broad-based weighted average: the market standard

The broad-based weighted average formula is the model most commonly seen in Singapore shareholders’ agreements and constitutions today. Rather than resetting to the new issue price outright, it recalculates the conversion price using a formula that weighs the size of the new issuance against the company’s existing fully diluted share capital. A large dilutive issuance moves the conversion price more; a small one moves it only slightly.

The standard formula (expressed in the form most Singapore precedent documents use) is:

New Conversion Price = Old Conversion Price × (A + B) / (A + C)

Where: A = the number of shares outstanding immediately before the new issue (on a fully diluted, as-converted basis); B = the number of shares that the consideration received for the new issue would have purchased at the old conversion price; C = the number of shares actually issued in the new round.

Because the formula folds in the size of the round (through variable C) and the shortfall in consideration (through variable B), a modest down round produces a modest adjustment, while a severe down round produces a larger one, but never as severe as a full ratchet reset. The term “broad-based” refers to the convention of calculating A on a fully diluted basis, counting all outstanding options, warrants and convertible instruments, rather than a “narrow-based” calculation that counts only issued shares and therefore produces a steeper, more investor-favourable adjustment.

Why weighted average has become the negotiating default

Broad-based weighted average is generally regarded as the fairer compromise: it protects the investor’s economic interest without disproportionately punishing founders or converting a modest down round into a change-of-control-style reset. Singapore-based venture funds, corporate venture arms and angel syndicates now routinely propose broad-based weighted average as the opening position in term sheets, reserving full ratchet for situations where the investor is providing rescue or bridge financing to a company already in financial difficulty.

Carve-outs that should always be negotiated

Whichever model is used, a well-drafted anti-dilution clause should carve out issuances that should not trigger any adjustment at all. Typical exclusions in Singapore shareholders’ agreements include shares issued under an approved employee share option scheme (see our guide to setting up an ESOS in Singapore), shares issued on conversion of existing convertible instruments already on the cap table, bonus issues and share splits, and shares issued as consideration in a bona fide acquisition rather than a cash fundraising round. Without these carve-outs, routine housekeeping issuances, such as topping up an option pool, could inadvertently trigger a ratchet that nobody intended.

The constitutional and Companies Act mechanics

An anti-dilution provision is a contractual promise in the shareholders’ agreement, but it only has legal effect against the company and third parties if it is reflected in the rights attaching to the relevant class of shares under the company’s constitution, or in the specific terms of issue lodged with the Accounting and Corporate Regulatory Authority (ACRA) when the preference shares are allotted. A shareholders’ agreement clause that is never mirrored in the constitution binds only the parties to that agreement and gives the protected investor a breach of contract claim, not an automatic conversion adjustment.

Two further points are worth flagging to directors and company secretaries handling a down round:

First, any adjustment to the conversion ratio of an existing class of shares, because it changes the rights attached to that class relative to ordinary shareholders, can be treated as a variation of class rights. Section 74 of the Companies Act 1967 requires that variation or abrogation of rights attached to a class of shares follow whatever procedure the constitution specifies (typically consent of a specified proportion of that class, or a separate class meeting), and failing that, by a resolution passed by holders of at least 75% of that class. Holders of at least 5% of the affected class who did not consent may apply to the Court within one month to have the variation cancelled. Anti-dilution adjustments that are triggered mechanically under a pre-agreed formula are less likely to be challenged as an unconsented variation than an ad hoc renegotiation, which is one more reason the formula should be precisely drafted into the constitution at the time the preference shares are first issued, not improvised later.

Second, every new allotment of shares, whether at par, at a premium, or at a discount to an earlier round, still requires the private company to lodge a return of allotment with the Registrar under section 63 of the Companies Act 1967, including the class of shares, the amount paid on each share, and the updated members’ particulars. The allotment does not take effect until the electronic register of members is updated by the Registrar. Getting the class of shares and paid-up amount right in that return matters directly to how the anti-dilution formula is later calculated, since the formula depends on an accurate fully diluted share count. For the mechanics of that filing, see our guide to allotting new shares in a Singapore company.

Practical drafting checklist

  • Specify clearly whether the protection is full ratchet or broad-based weighted average, and if weighted average, define A, B and C precisely, including whether options and warrants are counted.
  • Carve out ESOS issuances, bonus issues, conversions of existing instruments, and acquisition consideration shares from triggering an adjustment.
  • Mirror the mechanism in the company’s constitution or the specific terms of issue for the preference shares, not only in the shareholders’ agreement.
  • Consider a sunset clause so the protection lapses on an initial public offering or a qualifying exit, which is standard market practice.
  • Coordinate the adjustment with the company’s share allotment and transfer procedures so the register of members and register of substantial shareholdings stay consistent with the adjusted conversion ratio.
  • Review anti-dilution terms alongside any exit or succession planning, since a ratchet triggered years after the original round can materially change the economics of a later sale; see our business succession planning guide for how ownership transfer terms interact with existing investor protections.

Conclusion

Anti-dilution provisions sit quietly in the rights attaching to preference shares until a down round forces them into the open, at which point badly drafted clauses become expensive and contentious. Full ratchet is simple to state but harsh in application; broad-based weighted average is the model most Singapore founders and investors now settle on because it scales the adjustment to the size of the dilutive event. Whichever model your shareholders’ agreement uses, the clause is only as effective as its mirror in the company’s constitution, its carve-outs, and the accuracy of the underlying share register. Getting this right at the term sheet stage, rather than during a difficult down round negotiation, is far cheaper for everyone involved.

Companies considering a new funding round, and directors reviewing whether an existing anti-dilution clause has been triggered, should have their company secretary check the constitution and share register before signing anything.

To speak with the team at Raffles Corporate Services, you can email [email protected] or call, SMS, or WhatsApp +65 8501 7133. We are happy to assist with any queries.

The Editorial Team, Raffles Corporate Services