Don't make the mistake of celebrating your percentage. That number on the napkin, in the pitch deck, on the SAFE, it means almost nothing until you see what survives.
I've watched smart physicians walk away from a clinical shift to build something real, only to learn two years later their "10%" turned into 1.2% and their common shares were worth zero after preferences. Not because the startup failed. Because they never protected the equity in the first place.
Here's how it happens: you sign early. The company raises money. The option pool gets expanded to hire engineers you've never met. A stack of SAFEs you didn't know existed converts. A liquidation preference gets added that says investors get paid 2x before you get a dollar. Your vesting gets triggered the wrong way when you cut back clinical hours. One by one, your ownership is sliced thinner while the headline number stays in your head.
Owning shares is not the same as owning value. Especially with preferred vs. common. You can own 5% on paper and still get nothing in an acquisition that looks like a win from the outside.
This is a mistake-avoidance guide. Not a hype piece.
This content is for educational purposes only and is not financial advice, not legal advice, and not tax advice. Every cap table is different and figures vary. Before you sign or invest time or money, consult a qualified professional.
Startup Equity Looks Big on Paper, Then Quietly Shrinks
Physicians are trained to trust titles and credentials. Startup equity doesn't work like that. The percentage they tell you is a story. The cap table is the truth.
Most early equity disappears in four quiet ways:
First, dilution. Every new round issues new shares. Your 100,000 shares don't shrink, but the pie gets massively bigger. Your 8% becomes 4%, then 2%.
Second, option pool expansion. Investors force the company to set aside 15-20% for future employees before their money goes in. That dilution hits you, not them.
Third, vesting and repurchase. That four-year vest with a one-year cliff? If you leave, reduce hours, or get pushed out as Chief Medical Officer because you're still practicing, the company can repurchase your unvested shares for pennies. Or worse, vested shares if you signed a bad buyback clause.
Fourth, preferences. Preferred investors get paid first. If they have 1x or 2x liquidation preference plus participation rights, there might be nothing left for common holders in a $30M sale, even though you're still listed as an owner.
Don't protect the headline. Protect the outcome.
The Biggest Mistakes That Make Physician Equity Disappear
I've seen these same five mistakes kill physician equity. Every time, the doctor says, "But they said it was standard."
Mistake 1: You believed the headline percentage without seeing fully diluted.
"Doctor, you'll get 5%." 5% of what? The pre-money? Post-money? After the option pool? After the $2M in SAFEs that haven't converted yet?
If you don't see the fully diluted cap table, meaning every share, option, warrant, SAFE, and convertible note converted, you don't know what you own. I've reviewed deals where a physician thought she had 7% and fully diluted she had 2.9% on day one.
Always ask: What's my ownership on a fully diluted basis, including the new option pool and all outstanding convertibles?
Mistake 2: You ignored vesting, cliffs, and repurchase traps.
Vesting is where founders lose shares without even arguing. Four-year vest with 12-month cliff means zero if you're out at month 11. And many physician founders have a side letter: if you stop being "actively involved," the company can repurchase vested shares at original issue price. $0.001 per share.
Check: What triggers repurchase? Is there single or double-trigger acceleration if you're terminated? What happens if you go back to full-time clinical?
Mistake 3: You signed SAFEs and convertible notes like they were harmless.
SAFEs are not safe for founders. They convert later, usually at a discount with a valuation cap, and flood the cap table with new shares you didn't model. A stack of $1.5M in SAFEs with a $6M cap can wipe out 20% of the founders in one conversion event at Series A.
Don't make this mistake: signing their SAFE template because a friend said it was "founder friendly." Read the cap, discount, pro rata rights, and MFN.
Mistake 4: You didn't understand common vs. preferred.
This is the painful one. You hold common. Investors hold preferred with liquidation preferences. In a sale, they get their money back first, sometimes 2x, then share in the rest. You can be a 10% common holder and get $0 in a $20M exit because preferences ate it all.
If you can't explain liquidation preference in your deal, you shouldn't sign it.
Mistake 5: You gave away equity too early, to too many people, with no milestones.
The generous physician advisor grant. 2% to a residency friend for "helping with the deck." 1% to a consultant who made three intros. No vesting. No performance. Those early grants compound and never come back. And they dilute you later.
Use milestone-based vesting for everyone. Even cofounders.
How to Protect Your Equity Before It Slips Away
Protection isn't about being aggressive. It's about being clear. Before you sign anything, do this.
1. Demand the actual cap table. Not a summary.
You want a spreadsheet with names, share classes, options, strike prices, SAFEs, notes, vesting status. If they won't share it, walk. I tell physicians: no cap table, no credibility work. Your name and license have value. Treat them that way.
2. Read every line like you'd read a consent form.
Vesting schedule. Cliff. Acceleration. Repurchase rights. Board approval rights. Drag-along. Anti-dilution. Pay special attention to "good leaver / bad leaver" and "involuntary termination." If those terms aren't defined in your favor, you're exposed.
3. Negotiate for control, not just count.
Share count is vanity. Control is protection. Ask for information rights, monthly financials, cap table updates. Ask who approves new dilution, new option pool increases, or liquidation preference changes. If you're a true cofounder, ask for a board seat or observer seat. If you're an early advisor, at least get pro rata rights to maintain your percentage.
4. Get a real startup lawyer. Not your cousin who does real estate.
This is not the place to save $2,000. I've seen handshake deals where the physician was promised 8% and the incorporation docs showed 2% with four-year vest and company repurchase at $0.0001. No lawyer reviewed it for 18 months. By then, leverage was gone. Get counsel before you sign.
5. Model the dilution yourself. In writing.
Ask them to model what your stake looks like after a $3M Series A at a $15M post-money and a $15M Series B at a $50M post-money with 15% option pool refresh each time. If they can't or won't, you build the model. You'll quickly see if your 5% today is 1.5% tomorrow with zero value after preferences.
Red Flags That Should Make You Pause Before Signing
If you see any of these, stop. Don't sign under pressure. Pressure is a tactic.
Red flag: "We'll figure out the exact equity later. Trust me, it'll be fair." Fair isn't a term sheet. If there's no written cap table, no stock purchase agreement, no vesting doc, there is no equity. Only a promise.
Red flag: The advisor stack eats the company. When three "strategic advisors" who do nothing hold 8% combined and the two working founders hold 30%, the math is broken. You'll get diluted endlessly to fix it.
Red flag: You're the credibility but get zero visibility. They want your MD, your photo, your talks, your access to a hospital system, but they won't show you SAFE terms, term sheets, or board consents. That's not a company. That's using you for marketing.
Red flag: "It's standard, you need to sign today." Nothing standard needs a signature in 24 hours. That line means they don't want you reading the repurchase clause. Every bad deal I've unwound came with urgency.
Red flag: The CEO can't explain dilution or down rounds. Ask a simple question: What happens to my ownership if we raise a down round with full-ratchet anti-dilution? If they blank out, or say "that never happens," you're dealing with someone who will accidentally wipe you out.
Summary: The Safe Way to Think About Physician Startup Equity
Equity doesn't disappear because you're unlucky. It disappears because you didn't lock it down.
Optimism won't protect it. Documentation does. Modeling does. A lawyer who does this every week does.
So flip your habit. Before you celebrate the percentage, ask: What's my fully diluted percentage? What's the vesting and repurchase? What class of stock do I have, and what preference sits on top of me? What does this look like after two more rounds?
And protect your time like you protect your capital. An unclear deal isn't a small mistake. It's months of clinical credibility and nights and weekends you'll never get back.
Say no to fuzzy deals early. Say yes to clear ones with paperwork that actually protects you.
