Weighted Average Anti-Dilution

The standard form of anti-dilution protection. The conversion price is reduced in proportion to how much cheap stock was sold and how much of the company it represented: new price = old price × (A + B) ÷ (A + C), where A is the shares outstanding before the round, B the shares the new money would have bought at the old price, and C the shares it actually bought. Broad-based counts options in A; narrow-based does not, and bites harder.