A percentage of what, exactly
When you own 1% of a startup, you own 1% of its fully diluted share count, every share and option that exists or is reserved to exist, not just the shares issued today. That distinction matters because most early-stage companies reserve an option pool, typically 10-15% of the company, for future employee equity, and that pool is usually carved out of existing holders' ownership, including yours, before or at the round you invest in.
Dilution: the mechanism, not the villain
Every time a company raises a new round, it issues new shares to the new investors. Since the total number of shares grows, everyone else's percentage ownership shrinks, this is dilution, and it happens whether the round goes well or badly. Dilution is not a red flag by itself: if the company's total value is growing faster than your percentage is shrinking, your shrinking slice is still worth more in absolute dollars. The problem case is a round that dilutes you heavily without the valuation growing enough to compensate, or worse, a down round (Lesson 27) where the valuation falls.
Why this matters before you ever see a cap table
Two consequences follow directly. First, the percentage you're offered today should be read as a starting point that will shrink, not a fixed number, when you think about the ownership needed for a check to matter at exit. Second, pro rata rights (Lesson 9) exist specifically to let you put in more money at later rounds to slow this shrinkage, which is one of the few tools an angel has to defend a position they believe in.
Checkpoint
- Ownership percentage is measured against the fully diluted share count, including reserved option pools.
- Dilution happens automatically at every new round; it's a mechanism, not necessarily a problem, unless the valuation isn't growing fast enough to compensate.
- Ownership offered today should be read as a number that will shrink over the company's life, not a fixed stake.
If anything here still feels unclear, ask before moving to Lesson 5.