An anti-dilution provision can be a clause included in a shareholders’ agreement that protects investors against a reduction in the value of their existing stake in a company if the company later issues new shares at a lower price. In other words, these provisions facilitate protection against dilution of the value of an investor's stake in the company.

A dilution, in the context of the stock market, is the provision that reduces a shareholder's ownership percentage in a company, relative to the size of other shareholders in the same company. It happens when a company issues additional shares or securities to the public, which increases the total number of outstanding shares and reduces each shareholder's percentage of ownership.

Anti-dilution provisions come into play when a company is considering issuing shares at a lower price than the investor paid when initially investing in the company. For example, if an investor purchased 10,000 shares at $10 each, but the company later issued the same number of shares to another investor at $8 each, then the value of the investor's stake would be reduced by 20%.

To protect investors from such a situation and to ensure that their investments are not diluted, anti-dilution provisions can be included in the shareholders’ agreement. This provision requires the company to compensate investors by providing additional shares, typically at a discounted rate, to offset the potential dilution effects of future share issuances.

One of the most common types of anti-dilution protecting investors is weighted-average anti-dilution protection. Here, the added shares that investors receive are based on the average weighted market price of the new shares issued by the company. This means that if the new shares were issued at a lower price than the investor initially paid, then the investor will receive a fixed number of extra shares to compensate for the reduced value of their stake.

In conclusion, anti-dilution provisions are an important and valuable safeguard for investors looking to protect the value of their investments in the company. By ensuring that the value of their stake is not compromised if the company issues new shares at a reduced price, these provisions can provide investors with peace of mind in knowing their investments are safe.