Dilution

How your ownership share shrinks each time new shares are issued.

Also known as: dilution, equity dilution, ownership dilution

Dilution is the shrinking of your ownership percentage as new shares are issued to investors and employees. The company can be worth far more while your slice narrows: owning 60% of a $50M company beats owning 100% of nothing, but every round re-prices what your percentage means.

founders 100% → seed sells 20% → founders 80%
            → Series A sells 20% of new total → founders ~64%

Dilution is neutral — what matters is value per share growing faster than percentage shrinks. The dangers are specific, not general: excessive early dilution (founders below motivation thresholds before Series B), surprise dilution (unmodeled SAFEs converting), and down-round dilution with anti-dilution ratchets multiplying the pain.

The classic mistakes:

Optimizing percentage over value. Refusing a good round to “avoid dilution” while the company starves. A smaller slice of a much bigger pie is the entire venture trade — take it when the capital accelerates value.
Unmodeled instruments. SAFEs, notes, option pool increases and warrants all dilute at conversion. Model fully-diluted ownership continuously, not at 2am before the round closes (see cap table).
Founders diluted past motivation. Single-digit founder stakes pre-exit breed checked-out founders. Protect founder ownership through round sizing and top-ups as a deliberate policy.
Confusing dilution with value loss. Percentage down plus value-per-share up equals winning. Track dollars of your stake, not just percent — and understand pre/post money math cold before signing anything.

The mindset: dilution is the price of growth capital. Pay it gladly for acceleration, model it always, and never be surprised by your own cap table.