Roughly once per decade, a company comes along that makes a lot of people rich: facebook, Google, Microsoft. Dozens—in facebook's case, hundreds—of people realized seven/eight-figure dollar wealth at IPO.

These are transformative events for a region, and a generation. They make work permanently optional, provide seed capital for thousands of businesses, and become the stuff of media sensation, and gossip between friends.

But they're vanishingly rare.

Here's the typical early-employee math:

1. 0.5% grant at hire, vested over four years
2. Company raises $150 million
3. $1.0 billion IPO/trade sale value

Assume the employee gets diluted 50% by subsequent financings. That means they'll get 0.25% of $850 million, assuming a 1x liquidation preference on the $150 million. Our hypothetical employee walks away with $2.1 million over four years (more likely to be 6-7), pretax, minus option exercise price (which will be low if they joined early enough to get the full 0.5%).

Not bad. But in order for this to work out:

• The opportunity must support a billion-dollar exit (relatively easy to spot)
• The employee must identify the opportunity early enough to get the full 0.5% (harder)
• The company must execute at a very high level, over a long period of time (almost impossible to know)

My point: there are few paths to becoming a dollar millionaire if the company you join won't sell for a billion; even a (much larger) 2-3% stake in something that sells for $100 million won't clear the bar after dilution, especially if the firm raises too much.

I'm not saying you shouldn't work at a small company. But if wealth is your goal, you'd be better-served looking elsewhere, doubly so when there's a lot of dilutive venture capital involved, and no shot at a billion-dollar outcome.

A billion or bust.