For many founders, the first time the question of paying tax on unrealized capital gains comes up is not during a funding round or a board meeting. It usually appears in a quieter moment. You log into your cap table platform, review an updated 409A valuation, or see your company stock valued far above your original strike price. The number representing your equity is significantly higher than it used to be.
And then you wonder: if the value has increased that much, is there a tax bill hiding somewhere?
The short answer is that taxes on unrealized capital gains are generally not taxed under current U.S. law. But different types of equity, different elections, and different timing decisions can create tax consequences long before a full liquidity event.
What Unrealized Capital Gains Actually Mean
An unrealized capital gain is simply an increase in value on something you still own. If you acquired founder shares at a very low valuation and the company is now worth substantially more, that increase represents a gain. Because you have not sold the shares, the gain remains unrealized.
This concept applies whether the asset is public stock, private equity, or an early-stage investment. As long as no sale or disposition has occurred, the gain stays on paper. There is no capital gains tax triggered merely by appreciation.
For founders, this distinction matters because equity growth often happens years before liquidity. The numbers can become very large without any cash changing hands. That gap between paper wealth and actual liquidity is where confusion about taxes often begins. Understanding that unrealized appreciation alone does not create a tax bill is a starting point.
Why Unrealized Gains Are Not Taxed Today
The U.S. tax system is built around the concept of realization. Income is typically taxed when it is received or when a gain is realized through a transaction. If asset values fluctuate but nothing is sold, the tax system generally does not step in.
As markets move daily and private company valuations shift with each funding round, so taxing assets annually based on estimated values would introduce significant complexity. Instead, the system waits for a sale or other taxable event.
For founders holding common shares or long-term investments, this means appreciation alone does not generate capital gains tax. The gain is deferred until you choose, or are required, to sell.
However, appreciation and taxation can intersect indirectly, hence certain equity decisions create taxable income even though you still hold the underlying shares. That is where planning becomes more important.
When Founders Can Trigger Tax Without Selling
While unrealized gains themselves are not taxed, founders frequently encounter situations where a tax bill arises without a traditional sale. The key is recognizing that the tax is triggered by a specific event, not by appreciation alone.
Exercising Non-Qualified Stock Options
With non-qualified stock options, the act of exercising can create taxable income. The difference between the strike price and the fair market value at exercise is generally treated as ordinary income.
You may still hold the shares after exercising. You may not have sold anything. Yet income has been recognized because compensation was effectively received in the form of discounted shares.
This is where modeling becomes essential. Before exercising, it helps to project the ordinary income generated, the resulting federal and state taxes, and whether you have sufficient liquidity to cover them.
Incentive Stock Options And Alternative Minimum Tax
Incentive stock options introduce a different layer of complexity. Under regular tax rules, exercising ISOs does not create ordinary income. However, the spread at exercise can be included in income for Alternative Minimum Tax (AMT) purposes.
That means you could face an AMT liability even though you still hold the shares and have not sold them. The gain is unrealized for capital gains purposes, but it is relevant for AMT calculations.
As AMT exposure depends on your broader income picture, it is wise to run projections before exercising significant ISO grants. A well-timed exercise can reduce long-term taxes, but an unplanned one can create short-term strain.
Restricted Stock And The 83(b) Election
For founders who receive restricted stock early, the 83(b) election often represents one of the most important tax decisions they will make.
Without filing an 83(b) election, taxes are generally due as shares vest, based on their value at each vesting date. If the company’s valuation rises quickly, this can lead to substantial ordinary income during the vesting period.
By filing an 83(b) election within 30 days of the grant, you elect to be taxed upfront on the value at grant. If the value is low at that time, the tax cost can be minimal. Future appreciation is then taxed as capital gain upon sale.
This choice does not change the fact that unrealized gains are not taxed annually. Instead, it determines whether early appreciation is captured at lower ordinary income levels or deferred into capital gains treatment later. The long-term impact can be significant.
As you can see, the common thread is not that unrealized gains are taxed. It is those specific equity events that convert part of that growth into taxable income under defined rules.
What Happens When You Eventually Sell
At some point, most founders experience a realization event. That could be an acquisition, an IPO, or a tender offer.
When shares are sold, the unrealized gain becomes realized. Capital gains tax applies to the difference between your basis and the sale price.
The rate depends on how long you have held the shares. If the holding period exceeds one year, long-term capital gains rates generally apply. If not, short-term rates apply and are taxed at ordinary income levels.
The start of the holding period varies depending on the type of equity. For restricted stock with an 83(b) election, it typically begins at the grant. For exercised options, it generally begins at exercise. For RSUs, it usually begins when shares are delivered at vesting.
These technical details can influence whether a large liquidity event is taxed at preferential long-term rates or at higher short-term rates. For founders facing significant exits, the difference is not trivial.
Equally important is preparing for the cash flow impact. Once a sale occurs, taxes are due in that tax year. Estimated payments may be required. Planning ahead allows you to allocate proceeds thoughtfully rather than reacting under pressure.
Policy Changes And The Bigger Picture
From time to time, proposals surface that would tax unrealized gains for ultra high net worth individuals. These discussions often receive media attention and can create understandable anxiety.
Under current law, unrealized gains are not taxed annually for most taxpayers. For founders, the more immediate planning concerns tend to revolve around option exercises, vesting events, and liquidity timing rather than annual taxation of paper gains.
Still, being aware of the broader policy landscape is part of responsible long-term planning. Equity-driven wealth often spans many years; staying informed allows you to adapt if the rules evolve.
Specialized Financial Advice For Tech Founders & Equity Compensation
The core answer remains straightforward. Under current U.S. law, you generally do not pay taxes on unrealized capital gains. Appreciation alone does not trigger capital gains tax.
What complicates things for founders is not the existence of unrealized gains. It is the interaction between equity compensation structures and the tax code. Exercises, vesting schedules, and elections can convert paper growth into taxable income under specific circumstances. When your net worth is concentrated in equity, it requires more than general guidance.
KB Financial Advisors works specifically with tech professionals and founders navigating stock options, RSUs, concentrated equity, and complex tax situations.
If you are approaching an exercise decision, a liquidity event, or simply want clarity on your exposure, we invite you to schedule a conversation.
Having a clear tax plan can help you to structure decisions to keep more of what you earn, instead of reacting under pressure.
