Stock, Options, or RSUs? What You Actually Own, When It Vests, and Whether Taxes Are Due
Updated: Sep 5
"They gave me equity" is one of the confusing phrases in personal finance. It can mean three completely different things — real shares you own today, a right to buy shares later at a locked-in price, or a promise of free shares once certain conditions are met. Each one has a different answer to the questions that actually matter: do you have to pay for it, when do you owe tax on it, and when can you actually sell it.
This post walks through the mechanics: what each instrument actually is, how vesting works for each one, when the IRS says you owe tax, and the handful of decisions that are worth getting right before you sign anything or let a big tax bill catch you off guard.
A quick note before we start: this is general education, not advice for your specific situation. Equity plans vary by company, and tax rules depend on your circumstances — the questions below are ones to bring to a CPA or financial professional who can look at your actual numbers.
Three different deals, one confusing word
Stock means real shares, owned outright, from day one. In practice this only really happens at the founding stage — a founder or very early employee is issued actual shares.
Options are a right to buy shares later, at a price that's fixed today (the strike price). Until you pay that price, you don't own anything — you own the right to become an owner.
RSUs (restricted stock units) are a promise: free shares, delivered once specific conditions are met, usually time-based employment and, at private companies, a liquidity event as well.
All three "vest," but vesting does a different job depending on which one you're holding. With stock, vesting removes the company's right to buy the shares back if you leave — you already own them; vesting just makes that ownership permanent. With RSUs, vesting is the opposite: nothing exists before it. There's no share to lose, because the share doesn't exist yet. Vesting is the moment it's created. Options sit in their own category, covered next.
If you're evaluating an offer, the first useful question isn't "how much equity am I getting" — it's "which of these three am I actually being offered?"
Do you have to pay for it?
This is the fastest way to tell options apart from the other two. With options, yes — you pay the strike price, fixed on day one, whenever you decide to exercise. Until you pay it, you're holding a right, not a share.
With stock and RSUs, there's nothing to buy. You're waiting on conditions — time, a vesting schedule, sometimes a liquidity event — rather than writing a check.
This is also why options get mistaken for free stock. They aren't. They're a locked-in price you're choosing to pay later, if you choose to pay it at all.
RSU vs stock options, before or after an IPO: the four cases
Whether a company is private or public changes the picture more than the instrument does. Four combinations cover almost every situation:
Options, pre-IPO. You pay cash to exercise, and the IRS treats that exercise as a taxable event (more on that below). You now own real shares — but there's no public market to sell them into.
Options, post-IPO. Same cash outlay, same tax trigger at exercise, but the shares are sellable the same day.
RSUs, pre-IPO. No cash required. At a private company, RSUs typically carry two vesting conditions — usually a time-based schedule and a liquidity event (the company going public or being acquired). Nothing is taxed, and nothing is really "yours" to sell, until both conditions are satisfied.
RSUs, post-IPO. No cash required, and each vesting date is its own taxable event — taxed as ordinary income on the fair market value of the shares that vest that day. The shares are sellable immediately.
Notice the pattern: the instrument determines whether you need cash and when tax is triggered relative to exercise or vesting. The company's stage — private or public — determines whether you can actually turn any of it into cash. That second variable is easy to lose track of, especially when an offer letter puts a single dollar figure on your equity as if it were guaranteed money in the bank.
Private-company equity is a real potential asset, but it's illiquid — the current norm is that a company stays private for a decade or more before any liquidity event. It's worth treating unvested or unsold private equity as a possible future outcome, not as funds you already have. I personally wouldn't plan a mortgage down payment around it until the actual liquidity event has happened.
Two taxes, two different moments
Equity compensation touches two separate tax regimes, and mixing them up is where a lot of the confusion — and the surprise tax bills — comes from.
Income tax applies when you receive value: at exercise for options, or at delivery (vesting, for a public company) for RSUs. It's taxed at your ordinary income rate, which is higher than the capital gains rate for most people. The IRS explains how this works for statutory and nonstatutory stock options in Topic no. 427, Stock options, and the full detail on how equity compensation gets reported lives in IRS Publication 525, Taxable and Nontaxable Income.
Capital gains tax applies later, at sale, only on the growth in value since you became an owner — the gap between what the stock was worth when you took ownership and what it's worth when you sell. That's taxed at the capital gains rate, which is lower than ordinary income for anyone who holds the asset for more than a year. IRS Topic no. 409, Capital Gains and Losses covers how those rates work.
The detail worth sitting with: you can owe real income tax on stock you're not able to sell yet — RSUs at a private company are the clearest example, and even at a public company, the shares withheld to cover taxes at vesting are a real cash event whether or not you were planning to sell.
Options only: exercise early, or wait
If you hold options, you have a decision RSU holders don't: when to exercise.
Exercising early — soon after grant, while the strike price and the stock's current value are close together — means a smaller taxable gap at the moment of exercise, so less of the value ends up taxed as ordinary income and more of the future growth falls into the lower capital-gains bucket when you eventually sell. The tradeoff is real: you're putting actual cash at risk for a stock that isn't liquid, and if the company doesn't work out, that cash is gone.
Waiting keeps your cash safer while the company's prospects become clearer, at the cost of a larger income-tax bill whenever you do exercise, since the gap between strike price and current value has had time to grow.
If you exercise early and want that lower tax treatment locked in, there's a hard deadline attached to it: you have to file a Section 83(b) election with the IRS within 30 days of exercising — no exceptions, no extensions. Filing it means you're taxed on today's (low) value; missing the window means you default back to being taxed on the value at each future vesting date instead. The IRS recently introduced a standard form for this — Form 15620, Section 83(b) Election — which can now be filed electronically. If early exercise is something you're considering, this is a date worth putting on a calendar the day you exercise, not a week later.
The break most people don't know to ask about: Section 1202 (QSBS)
Qualified Small Business Stock, under Section 1202 of the tax code, lets you exclude a meaningful portion — potentially all — of your gain from federal tax when you sell, if you've held qualifying stock long enough. The company has to qualify at the time your shares were issued (broadly: a small, active C-corporation), and the clock on the holding period starts the moment you actually own the shares — which is the second reason early exercise matters for option holders: it starts this clock sooner, not just the capital-gains clock.
The rules changed materially in 2025. For stock acquired after July 4, 2025, the One Big Beautiful Bill Act shortened the holding period into a tiered structure — a 3-year hold now qualifies for a 50% exclusion, 4 years for 75%, and 5 years or more for the full 100% exclusion — and raised both the per-issuer gain exclusion cap (from $10 million to $15 million) and the gross-asset threshold a company can have and still qualify (from $50 million to $75 million). Stock acquired before that date still follows the older rules: a flat 5-year hold for the full exclusion, capped at $10 million or 10x your basis. The statute itself is 26 U.S. Code § 1202, and eligibility is genuinely a documentation question — this is worth confirming with a CPA early, not after you've already sold.
If you leave the company
Leaving — whether you quit or you're let go — changes the picture immediately, and the rules aren't symmetric across what you're holding:
Unvested shares or options are gone the day you leave. There's no partial credit and nothing to negotiate.
Vested options usually come with a short window — often 90 days — to pay the strike price in cash, sometimes for stock you still can't sell if the company is private. If you don't exercise in that window, the options expire.
Vested shares you already own are sometimes still subject to a buyback right in the plan documents, even after vesting. It's worth actually reading that clause before you assume vested means fully yours.
Questions worth asking before you sign
If you're evaluating an offer that includes equity, here's what's actually worth understanding before you accept it — not a generic checklist, but the specific gaps that tend to cause the most confusion later:
Which instrument are you actually getting — stock, options, or RSUs?
Is the share count you were quoted today's count, or fully diluted, and will future funding rounds shrink it?
What's the actual vesting schedule, including any cliff?
If you have options, how long do you have to exercise after you leave?
When would you first owe tax, and roughly how much?
Has the company ever run a liquidity event or sale window before?
Are there buyback rights attached to shares after they vest?
And — if the company might qualify — would exercising early start the clock on the Section 1202 holding period sooner?
None of these require a finance background to ask. They just require knowing that "equity" isn't one thing, and that the number on your offer letter is a starting point for these questions, not an answer to them.
The takeaway
Stock, options, and RSUs are three different deals, not three names for the same thing. Stock is real ownership from day one. Options are a right you pay for, taxed at exercise. RSUs are a promise that turns into ownership at vesting, with no cash required either way. That's the first variable, and it's the one most offer letters gloss over.
Layered on top of it is the second variable, which matters just as much: whether the company is private or public. It doesn't change what you were promised, but it changes when tax hits and whether you can actually turn any of it into cash. Two people holding "the same" instrument can be in genuinely different situations depending on that one fact alone.
Vesting is not cash in hand, and tax can arrive well before you're able to sell anything — that gap is where most of the expensive surprises happen: a bill you weren't expecting, or a decision made under pressure instead of with a plan. None of this requires becoming a tax expert. It requires knowing which of a handful of variables — instrument, stage, vesting schedule, tax timing, and whether early exercise or the Section 1202 exclusion might apply — are actually in play for your specific equity.
So when an offer letter or a vesting notification uses the word "equity," the useful move isn't to take the number at face value. It's to ask which deal you're actually looking at, run the numbers with someone who can see your full financial picture, and decide from there.
Transparency Note: I'm the human behind the keyboard — the ideas, stories, and decisions here are mine. I collaborate with AI throughout the writing process: brainstorming, drafting, smoothing out grammar and flow, assisting with research, and creating the visuals you see throughout my posts.
Disclaimer: The information provided in this blog post is for educational and informational purposes only. I am an AFC® (Accredited Financial Counselor) Candidate, not a Certified Financial Planner (CFP), Certified Public Accountant (CPA), tax advisor, attorney, or Investment Adviser Representative (IAR). The content herein is not intended to be a substitute for investment, tax, or legal advice from a licensed professional. Always seek the advice of a qualified professional with any questions you may have regarding your individual financial situation. The opinions expressed are my own and do not represent the views of my current or former employer.
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