Explaining investment terms: Anti-dilution (or price protection)

Venture capital investors often require anti-dilution protection rights to protect the value of
their stake in the company, if new shares are issued at a valuation which is lower than that at which they originally invested (a down round). This protection usually functions by applying a mathematical formula to calculate a number of new shares which the investors will receive, for no or minimal cost, to offset the dilutive effect of the issue of cheaper shares.

There are several variations of the formula, each providing different degrees of protection. These include full ratchet protection, which will maintain investors' full percentage ownership at the same level or at the same value in down rounds. Other versions of the formula provide some compensation for the dilution, but allow the ownership percentage to fall; the most common of these is weighted average. The level of protection required by an investor depends on several factors, including the valuation of the company at the time of the investment and the perceived exposure to further financing requirements.

cog mechanismsWhile the basic concept remains the same, there are several different mechanisms used in Continental European jurisdictions to create this protection. In the UK, the mechanism of adjusting the conversion ratio of preferred shares to ordinary shares to adjust for dilutions can be used, although other methods, including the issue of shares for a nominal sum or bonus shares, are also used. The latter might involve the granting of options (or warrants as they are sometimes referred to), which are only exercisable if the anti-dilution provision is triggered.

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Protecting your money

Howard Palmer


Howard is a partner in the corporate technology group.

Angus Miln


Angus is a partner in the corporate technology group.