Meaning
Provisions in a company charter adjust the conversion ratio of preferred shares to protect investors from value loss during subsequent down rounds. These anti-dilution adjustments recalculate how many common shares each preferred share receives upon conversion. The protection operates when new shares are issued at a price lower than the price paid by the original investors.
Trigger Mechanism
Financing rounds executed at a valuation below the previous investment round activate the adjustment clauses. A down round forces an automatic reset of the conversion price. This process alters the ownership distribution to shield early venture backing from dilution.
Mathematical Model
Calculation methods vary between the harsh full ratchet mechanism and the more moderate weighted average approach. The weighted average method accounts for both the price and the volume of the new share issuance. A formula takes into account the outstanding share count prior to the new round alongside the total capital raised.
This approach preserves the initial investment ratio without disproportionately penalizing early common shareholders.
Financial Impact
Common shareholders suffer a larger reduction in their ownership percentage to accommodate the adjusted conversion rate of the preferred investors. Founders and employees often see their incentive pools diluted to a greater degree. This shift in the equity distribution changes the distribution of eventual exit proceeds.
Investors maintain their target shareholding while founders bear the dilution.