The offer letter arrived with a number in the salary line that was exactly $18,000 lower than what she was making. But then there were the options: 40,000 shares, vesting over four years with a one-year cliff. At the company's most recent 409A valuation, those options had a paper value of roughly $200,000. She accepted the job. Two years later, she got a better offer and decided to leave. That is when the education started.
Her story is not unusual. Across Silicon Valley, Austin, New York, and every other city where startups compete for talent, the same pattern plays out constantly. Promising professionals accept compensation packages that look generous on paper, discover too late that the fine print contains a set of financial consequences they were never warned about, and end up either trapped in jobs they want to leave or facing tax bills they cannot afford.
The Two Types of Options — and Why the Difference Matters
Most employees who receive stock options from startups are granted either Incentive Stock Options (ISOs) or Non-Qualified Stock Options (NSOs). The distinction sounds technical. Its financial consequences are anything but.
ISOs are typically granted to full-time employees and carry favorable tax treatment: you do not owe ordinary income tax when you exercise them, only when you sell. The catch is the Alternative Minimum Tax, which can apply at exercise and create a tax liability even if you never sell a single share. NSOs, often granted to contractors and advisors, are taxed as ordinary income at exercise — meaning the spread between the strike price and the fair market value becomes taxable the moment you exercise, whether or not you have sold anything.
Most startup employees have 90 days after leaving a company to exercise their vested options. After that window closes, the options expire. If you cannot afford the exercise price plus the tax bill, you lose everything you vested.
This 90-day window is the mechanism that traps employees at companies they want to leave. If the stock is worth enough that the tax liability is significant, and the company has not gone public or been acquired, there may be no way to sell shares to cover the bill. The choice becomes: exercise and take on tax debt you may not be able to pay, or walk away from years of vested compensation entirely.
The Vesting Trap
A four-year vest with a one-year cliff is the standard structure for startup equity. In plain terms: you receive nothing if you leave before twelve months, then one-quarter of your total grant vests at the one-year mark, with the remainder vesting monthly or quarterly over the following three years.
What this structure does, by design, is create a series of financial disincentives to leaving. Leave at month ten and you forfeit everything. Leave at month fourteen and you leave 75% of your grant behind. Leave at month thirty and you leave half. At every point in the vesting schedule, there is a compelling financial reason to stay just a little longer.
The company is not giving you equity. It is using equity to purchase your time in increments, and the price keeps resetting every time you think about leaving.
For job hoppers — professionals who move roles every two to three years as a deliberate career strategy — this structure is particularly destructive. Each move before a grant is fully vested represents an economic loss that rarely shows up in the headline compensation comparison. A $30,000 equity grant that is 50% vested when you leave is a $15,000 loss, invisible in the math of the new offer but very real in your long-term wealth accumulation.
What to Actually Negotiate
None of this means you should refuse equity. Startup equity has created genuine wealth for thousands of employees who joined at the right time and held on through an exit. What it means is that you should negotiate with full information.
Ask about extended exercise windows
Some employee-friendly companies have moved away from the 90-day post-termination exercise window to extended windows of one to ten years. This eliminates the forced-exercise trap. Ask directly: "What is your post-termination exercise window?" If the answer is 90 days, factor that into how you value the equity.
Understand the 409A valuation and preferred stack
Options are typically granted at the current 409A valuation, which is a tax-driven estimate of common stock fair market value. In most funding scenarios, preferred shares — held by investors — have liquidation preferences that get paid before common shareholders see a dollar. In a downside exit scenario, employees with common stock options may receive nothing. Ask for the capitalization table and the liquidation preference structure before accepting an offer.
Weight cash over equity early in a company's life
The earlier stage the company, the more uncertain the equity value. At pre-seed and seed stage, even large option grants carry enormous risk. Unless you have genuinely strong conviction about the company's trajectory, negotiate for higher base salary over larger option grants in early-stage roles.
Compare total compensation packages across companies — including equity, base, and bonus — at Oh My Job, where roles across startups and established companies are listed side by side.