A type of anti-dilution mechanism. A weighted average ratchet adjusts downward the price per share of the preferred stock of investor A due to the issuance of new preferred shares to new investor B at a price lower than the price investor A originally received. Investor A's preferred stock is repriced to a weighted average of investor A's price and investor B's price. A broad-based ratchet uses all common stock outstanding on a fully diluted basis (including all convertible securities, warrants and options) in the denominator of the formula for determining the new weighted average price. See Narrow-based weighted average ratchet.