IPO Tax Cost: RSU and Option Holders After Lockup

An employee who sells $2,000,000 of post-IPO stock the day a lockup period lifts — long-term holding, California residence — keeps about $1,218,000 after taxes and fees. That is 60.9 cents on the dollar. Move the same sale to Texas and the figure climbs past 76%; reclassify the gain as short-term and it sinks toward the low 50s. The spread between best and worst case on identical gross proceeds runs north of 25 percentage points, and almost none of it is visible in the wealth headlines that follow a hot debut.

The gap between the number on the screen at lockup expiration and the number that lands in a brokerage account is the entire subject here. RSU and option holders tend to anchor on share price times share count. The tax code anchors on holding period, exercise mechanics, and state of residence — three variables that an IPO does nothing to simplify.

The number that matters: net yield, not share price

Most coverage of an IPO stops at paper value. The figure worth tracking is what survives the round trip from grant to settled cash. The Finluxy Liquidity Event Net Yield captures it directly: net after-tax, after-fee proceeds divided by gross pre-tax proceeds, expressed as a percentage. For a liquidity event built on equity compensation, that single ratio compresses four separate decisions — when you exercised, how long you held, where you live, and what you paid your advisors — into one comparable figure.

Sources: SEC/Investor.gov (lockup); IRS Rev. Proc. 2024-40 and Topic 409 (LTCG); IRS Topic 559 (NIIT); California FTB / Tax Foundation 2025 (state rate). Net yield per Finluxy model.

How RSUs and options diverge at the IPO

RSUs and options that ride through an IPO do not land in the same place on the tax return, and the difference shapes every downstream number. The mechanics matter before the rates do.

Restricted stock units are taxed as ordinary income when they vest and settle. For an RSU that vests at or shortly after IPO, the share price on the settlement date becomes both the ordinary-income event and the new cost basis. According to IRS Publication 525, the fair market value at vesting is wages — reported on a W-2, subject to withholding. Whatever the stock does after that is a separate capital gains question, and the clock for long-term treatment starts at settlement, not at grant. An RSU holder who sells the moment a 180-day lockup period lifts has held the settled shares for roughly six months. That is short-term. The gain above the vesting-date basis is taxed at ordinary rates, the same brackets topping out at 37% for 2025 taxable income above $626,350 single or $751,600 married filing jointly (IRS Rev. Proc. 2024-40).

Options split along their own fault line. Non-qualified stock options (NSOs) generate ordinary income at exercise equal to the spread between strike and fair market value, again per Publication 525. Incentive stock options (ISOs) generate no regular-tax income at exercise, but the same spread is an adjustment for the alternative minimum tax — the well-known AMT trap on paper gains for anyone who exercises and holds across a year-end without selling. The holding-period reward is real: an ISO held more than two years from grant and more than one year from exercise produces a qualifying disposition taxed entirely at long-term capital gains rates. Miss either window and it is a disqualifying disposition, with the bargain element snapping back to ordinary income.

The practical upshot for lockup timing: the employee who exercised options well before the IPO and let the holding clock run can sell at lockup expiration into long-term rates. The employee whose RSUs vest at IPO cannot — not without waiting roughly another six months past the lockup. That waiting period is itself a cost, the subject of dedicated lockup period cost analysis that weighs tax savings against price risk on a concentrated position.

Building the net proceeds: a $2M long-term sale in California

Take the cleanest favorable case first. An employee exercised ISOs in the prior year, cleared the AMT event, satisfied both holding periods, and sells $2,000,000 of stock after the lockup period expires. Assume for modeling that basis is negligible relative to proceeds, so the gain approximates the gross — the typical shape for early-employee equity. California resident, single filer already at top brackets from the gain itself.

The stack runs in order. Federal long-term capital gains at 20%, because taxable income clears the $533,400 single threshold (IRS Topic 409). Net Investment Income Tax at 3.8%, because MAGI clears $200,000 and capital gains are net investment income (IRS Topic 559). California at 13.3%, since the state taxes capital gains as ordinary income with no preferential rate and the gain pushes past the $1 million Mental Health Services Tax line. Combined marginal rate: 37.1%.

Tax rates: IRS Rev. Proc. 2024-40, Topic 409, Topic 559 (2025); California FTB / Tax Foundation 2025. Model assumes negligible basis and top-bracket marginal treatment; fees illustrative. Net yield per Finluxy definition.

Now change one variable. The same employee holds RSUs that vested at IPO and sells at lockup — short-term. The federal layer is no longer 20%; it is the ordinary 37% top rate. NIIT still applies at 3.8%. California is unchanged at 13.3%, because the state never distinguished holding periods to begin with. Combined: 54.1% before fees.

Tax rates: IRS Rev. Proc. 2024-40, Topic 559 (2025); California FTB / Tax Foundation 2025. STCG taxed as ordinary income at 2025 top federal rate. Net yield per Finluxy definition.

Same $2M, same person, same city. The holding-period classification alone moves the net by $340,000. That is the cost of selling six months too early, and it is the single most expensive decision most RSU holders never realize they are making.

The state line is worth more than the IPO pop

Where the seller lives rewrites the bottom row. California’s 13.3% has no long-term carve-out, so a resident pays it on the full gain whether the holding clock helped or not. A Texas, Florida, or Washington resident pays zero state income tax on the same sale. (Washington’s 7% capital gains tax applies above a threshold but exempts certain transactions; the no-income-tax states proper levy nothing on this gain.)

Combined rates: federal LTCG 20% or ordinary 37%, plus NIIT 3.8%, plus CA 13.3% where applicable (IRS 2025; California FTB / Tax Foundation 2025). All scenarios net of ~$40,000 illustrative fees. Net yield per Finluxy definition.

One trap deserves a flag before anyone books a one-way flight to Austin. California, like New York, asserts source-based taxing authority over compensation income tied to work performed in-state — including equity earned while a California resident, even if the sale happens after a move. The ordinary-income portion of RSUs and NSOs (the vesting or exercise spread) is generally California-source wages if the work was performed there. The capital gains portion accruing after departure is typically taxable only by the new state of residence. Splitting those two cleanly is where the planning lives, and it is documented in the full California tax on liquidity events breakdown. A poorly-timed move captures none of the state savings and all of the audit risk.

What the data shows that most coverage misses

Run the four scenarios together and a non-obvious pattern emerges: for a California seller, fixing the holding period is worth more than fixing the state. Moving from short-term to long-term in California lifts net yield from 43.9% to 60.9% — a 17-point gain. Moving from California to a no-tax state at long-term rates lifts it from 60.9% to 74.2% — a 13-point gain. The holding-period decision, which costs nothing but patience and price exposure, beats the residency decision, which costs a relocation.

Most IPO commentary inverts this. It treats the state move as the sophisticated play and the holding period as a technicality. The arithmetic says the opposite for the typical RSU holder, because the short-term-versus-long-term swing on the federal side (37% versus 20%, a 17-point rate gap) is simply wider than California’s entire 13.3% rate. The federal classification is the larger lever, and it is the one fully inside the employee’s control through sell-timing. That framing rarely survives contact with a marketing deck promising newly-minted millionaires.

Methodology

FAQ

What this means for a $150k+ household

For a household already at $150k+ in ordinary income, an IPO liquidity event does not arrive in a vacuum — it lands on top of wages that have likely already filled the lower brackets, which means nearly every dollar of gain is taxed at or near the marginal top. The planning questions are concrete. Can vested RSUs wait the additional months past lockup to convert short-term into long-term, and is the price risk on a concentrated, freshly-public position worth the rate savings? For option holders, was the exercise early enough that the long-term clock has already run? A structured sell-down — staged across the lockup expiration and the following tax year, sometimes through a pre-arranged trading plan that lets insiders sell during blackout windows, detailed in the mechanics of a 10b5-1 plan for pre-IPO sellers — can spread gains across brackets and calendar years rather than detonating them in one return.

The diversification math runs parallel to the tax math. A position worth $2M at lockup that the holder won’t sell for tax reasons is a position fully exposed to a post-lockup price decline, which is common as insider supply hits the float. The tax saving from waiting can be erased many times over by a 30% drop in the stock, and that trade-off is the heart of diversifying after a windfall on a tax-efficient path. The household earning $150k+ should weigh net yield against concentration risk as a single decision, not two. Where the gain is large enough and the residency picture genuinely mobile, the state question is worth modeling against the broader $2M liquidity event net yield by state — but only after the holding-period lever, the cheaper and larger of the two, has been pulled. For employees comparing an IPO against other exit structures, the same net-yield discipline applies to an all-cash company acquisition employee net outcome, a pre-IPO secondary sale of private stock, and the deferral available through rollover equity tax deferral. A coordinated read across event types, anchored in the broader liquidity event tax guide, is what separates the seller who keeps 74 cents from the one who keeps 44.