Answer (2026): A stock position is concentrated when one company is more than 10 to 15% of your household's investable assets. Most people measure it wrong: they check one brokerage account and skip the spouse's shares, the ESPP, the vested-but-unsold grants, and the options sitting in the same employer that pays the salary. The playbook is short. Measure the real number once, write a one-sentence hold-or-sell policy, then evaluate four families of fixes with your advisor: staged selling, exchange funds, charitable gifting of appreciated shares, and collars. Each one trades something for something.
Context: Best for equity-comp executives and post-liquidity founders, households earning $150K to $2M, where one ticker has grown past comfortable and keeps growing back after every vest.
Action: Add up every share of your employer across every household account, divide by total investable assets, and write the percentage down. If it is above 10%, the Year-End Tax Projection shows what this year's room to sell looks like.
Last reviewed: June 11, 2026.
- Concentration is a household number, not an account number. Spouse holdings, ESPP shares, vested-but-unsold RSUs, and exercisable options all count, and they all sit on top of a paycheck from the same company.
- The risk is not abstract. Since 1980, roughly 40% of Russell 3000 stocks have suffered a 70% or greater decline from peak and never recovered. In tech, about two-thirds.
- If you have a vest schedule, diversification is not a project, it is a treadmill. Every vest rebuilds the position you just trimmed, which is why a written policy beats a one-time cleanup.
- The four fixes are staged selling (pay tax now, simplest), exchange funds (defer tax, give up seven years of liquidity), charitable gifting (skip the gain, give up the asset), and collars (keep the asset, accept cost and complexity).
- None of this executes itself. Trading windows, 10b5-1 cooling-off periods, and tax-year boundaries make the calendar the real constraint, and the calendar is a coordination problem.
- One company's stock is more than 10% of what your household owns, and the next vest, ESPP purchase, or lockup expiration will push it higher.
- You sold some shares once, felt the tax bill, and have avoided the topic since.
- You are a founder or early employee sitting on a low-basis position after an IPO or acquisition, with most of your net worth in one ticker for the first time.
Read these three statements. If two apply, this playbook was written for you:
- You could not say, within five percentage points, what share of your household's investable assets is in your employer's stock right now.
- You and your spouse have never added your holdings of the same company together in one place.
- You have no written rule for what happens to new shares when they vest. Each vest gets decided by mood, or not decided at all.
Every guide on page one of Google will tell you 10 to 15% in a single stock is the line where planners start paying attention. Fine. But the percentage only means something if the numerator is honest, and for equity-comp households it almost never is.
The honest numerator includes:
- Your shares in taxable brokerage, IRAs, and the 401(k) company-stock fund.
- Your spouse's shares of the same company, in their accounts. Two people at the same employer, or one spouse holding the other's old employer stock, is common and almost never aggregated.
- ESPP shares, including the ones from purchase periods you forgot about.
- Vested-but-unsold RSUs sitting in the equity portal, which are just stock now, whatever the portal calls them.
- Exercisable options, at intrinsic value, because they move with the same ticker.
Then remember what sits next to the portfolio: the same company very likely pays your salary, your bonus, your health insurance, and your unvested grants. The stock can fall and take your income with it in the same quarter. One company, carrying both the paycheck and the portfolio.
This is the math behind the household balance sheet view: concentration hides in fragmentation. Five accounts that each look fine can add up to a household that does not. It is the same blind spot that shows up in what high-income families miss, and the fix is the same: one place where the whole picture is visible.
J.P. Morgan's long-running study of concentrated positions (The Agony and the Ecstasy) looked at the Russell 3000 since 1980 and found that roughly 40% of stocks experienced a catastrophic loss: a decline of 70% or more from peak that never came back. For technology companies, the rate is about two-thirds. The market as a whole did fine over that period. The median single stock did not.
Holding a big position in the company you work for can still be a reasonable choice. People close to a business sometimes have real conviction, and sometimes they are right. The point is narrower: a position that size deserves an explicit, written decision, made once and reviewed annually, instead of a default that compounds while nobody is looking.
The page-one guides treat concentration as a one-time cleanup. For anyone with a vest schedule, it is not a problem you solve, it is a flow you manage. Sell down to a comfortable 8% in March, and the June vest pushes you back to 11%. The ESPP purchase in July adds more. By the time you act again, you are back where you started, except the basis lots are messier.
A one-time diversification project fails against a quarterly rebuild. What works is a standing rule that handles new shares by default, which is why the policy comes before the strategy menu, not after. If RSUs are the engine of the rebuild, the RSU Vesting Tax Guide covers the other half of the problem: the withholding gap that makes every vest a tax event as well as a concentration event.
Before evaluating any strategy, write one sentence that answers what happens to employer stock by default. Examples of the shape:
"We sell enough of every vest at delivery to keep employer stock under 10% of investable assets, and we review the target each January."
"We hold everything until the position crosses 15%, then sell the oldest long-term lots back to 10% in the next open window."
The content matters less than the existence. A written sentence turns every future vest from a decision into an execution, removes the per-quarter agonizing, and gives your advisor something concrete to push against. Decide it once, with the whole household in the room, and log where you can both find it. (Households that keep decisions like this in X1 can point their advisor at the policy and the holdings behind it in one link, which is what makes the annual review a 20-minute conversation.)
These are the four families everything else is a variation of. None of them is advice; each is worth evaluating with your advisor against your basis, bracket, and timeline, because each one trades something real.
| Approach | What it does | What it costs you | Where it tends to fit |
|---|
| Staged selling | Sells the position down over one or more tax years | Capital gains tax now, paid in installments you control | Default starting point; pairs with a written policy |
| Exchange fund | Swaps your shares for units of a diversified pool, no sale today | Seven years of illiquidity, fees, and the tax bill still waits at the end | Very low basis, no near-term cash need, position too large to sell down inside a few tax years |
| Charitable gifting | Donates appreciated shares at full market value, skipping the embedded gain | The asset itself; you were giving anyway or you were not | Households with real giving plans, especially in high-income years |
| Collar | Buys a put and sells a call to box the stock into a price range | Premium costs, suspended holding period, non-qualified dividends, complexity | Locked-up or restricted shares you cannot sell yet but need to protect |
The unglamorous default. You sell a slice at a time, sized to your tax situation, until the position fits the policy. The 2026 mechanics worth knowing:
- Long-term gains (shares held over a year) are taxed at 0%, 15%, or 20%. The 20% rate starts above $545,500 of taxable income for single filers and $613,700 married filing jointly. The 0% band runs to $49,450 single and $98,900 joint, which matters in a sabbatical or early-retirement year more often than people expect.
- The 3.8% net investment income tax stacks on top above $200,000 of modified AGI single, $250,000 joint. Those thresholds are not indexed, so most of this audience pays it on every sale.
- Spreading sales across tax-year boundaries is the whole game: a December and a January sale are weeks apart on the calendar and a full year apart for tax purposes.
The practical move is a gain budget: decide how much capital gain this year can absorb without crossing a bracket or surcharge line, and sell to that number. The Year-End Tax Projection exists for exactly this, and the year-end planning guide covers the December sequencing. Selling lots with the highest basis first usually shrinks the bill for the same risk reduction; your advisor can run the lot-level math.
You contribute shares to a partnership alongside other concentrated investors and receive units of the pooled, diversified portfolio. No sale occurs, so no gain is recognized today. After seven years, you can redeem your units for a basket of stocks from the pool, still without triggering the original gain. Your old basis carries into the basket, so this is deferral, not erasure: the tax bill is still in there, waiting for whoever eventually sells.
The honest tradeoffs: your money is locked for seven years (leave early and you generally get your original shares back, not the diversified basket), the funds charge management fees on top of the structure, and tax law requires the fund to hold at least 20% in qualifying illiquid assets like real estate to keep its tax treatment, which changes what you actually own. Minimums are typically high, though newer entrants have pushed them down.
Worth evaluating with your advisor when the basis is very low, the position is large, and you will not need the money inside seven years. Not worth it for shares you could sell inside your gain budget anyway.
If your household gives to charity at all, giving appreciated employer stock instead of cash is usually the more efficient route. Shares held over a year are deductible at full market value, up to 30% of AGI for gifts to public charities (including donor-advised funds), with a five-year carryforward for the excess. The embedded capital gain disappears for everyone: you never realize it, and the charity does not pay it.
Two changes are new for 2026 under OBBBA, and most older guides have not caught up: itemized charitable deductions now only count above a floor of 0.5% of AGI, and for taxpayers in the 37% bracket the deduction's value is capped at 35 cents per dollar. Neither kills the play. Both make bunching (concentrating several years of giving into one high-income year, often through a donor-advised fund) more attractive, since the floor is paid once instead of annually.
This pairs naturally with the treadmill: a heavy-vest year spikes your income and your concentration at the same time, which is precisely when a large gift of appreciated shares does the most work. Sequencing it against the safe-harbor and withholding questions in the RSU guide is a CPA conversation, ideally in October, not April.
A collar buys a protective put below the current price and sells a call above it, bracketing the stock into a range. The call premium offsets some or all of the put cost, which is why you will hear "costless collar." It is the main tool for shares you cannot sell yet: lockups, blackout-heavy roles, or a position mid-negotiation.
The fine print is where collars earn their reputation for complexity. Pull the band too tight and the IRS can treat the whole thing as a constructive sale under Section 1259, taxing you as if you sold; practitioners commonly point to a band of roughly 15% or wider as the zone that avoids this, but this is exactly the kind of line you want a professional drawing. The straddle rules suspend your holding period while the collar is on (so shares do not age toward long-term treatment) and make dividends received non-qualified. Premiums, spreads, and the renewal problem (collars expire; concentration does not) all add friction. For insiders, every leg of this needs to clear counsel and the trading policy first.
A collar is a bridge, not a destination. It buys time until a window, a lockup expiration, or a liquidity event lets one of the other three fixes actually run.
Strategy menus make this sound like a portfolio decision. For executives and insiders, it is mostly a calendar decision.
Trading windows compress everything: if you can only sell four to eight weeks a quarter, the year has perhaps 20 sellable weeks, and a missed window pushes the plan a full quarter. A 10b5-1 plan fixes that by pre-committing the trades, but it has its own clock: since the SEC's 2023 rules took effect, officers and directors face a cooling-off period that runs to the later of 90 days after adoption or two business days after the next 10-Q or 10-K (capped at 120 days), and any modification restarts it. Everyone else waits 30 days. A plan adopted in March starts selling in summer. The vest calendar, the window calendar, the 10b5-1 clock, and the tax year all have to line up, and nobody owns that alignment by default.
This is the coordination gap. Your advisor sees the portfolio, your CPA sees the tax year, counsel sees the trading policy, and the equity portal sees the grants. The household sees all four, or no one does.
One working session with the right documents beats a quarter of email. Before the meeting, assemble:
- The household concentration number, computed the honest way above, with the account-by-account breakdown behind it.
- Lot-level detail for every block of employer stock: acquisition date, basis, and whether it is long-term yet.
- The next 12 months of vest dates and ESPP purchases, exported from the equity portal.
- Your trading-window calendar and a copy of the insider trading policy, if you are subject to one.
- Last year's return, so the gain budget and safe-harbor math start from reality.
- Your giving plan, if any, with amounts and timing.
- The one-sentence policy, even in draft. It is the agenda.
This packet is the difference between an advisor who can model three options in the meeting and one who spends the meeting asking for documents. Keeping it current in one place is the job X1's vault and advisor packet were built for: holdings, grant agreements, prior returns, and the written policy, shareable before the meeting instead of reconstructed during it. If multiple professionals touch this (advisor, CPA, counsel), the multi-advisor coordination guide covers who needs what.
- What is the household's true concentration percentage, counting both spouses, ESPP, vested-unsold shares, and options?
- What is the basis profile? How much of the position is long-term, and what would selling the highest-basis lots first cost this year?
- How much capital gain can this tax year absorb before the 20% rate, the NIIT, or a state bracket bites?
- Is there a written hold-or-sell sentence both spouses have agreed to?
- Which trading windows remain this year, and does a 10b5-1 plan (with its cooling-off period) beat waiting for them?
- If we already give to charity, why are we giving cash instead of appreciated shares?
- For any exchange fund pitch: what are the fees, what is in the qualifying-asset sleeve, and what happens if we need out in year four?
- You, this week: compute the household number. Every account, both spouses, one spreadsheet row per holding of the employer. Most people find 5 to 10 points they were not counting.
- Household, this month: draft the one-sentence policy and put the percentage target in it. Disagreement between spouses about the right number is normal and is exactly the conversation to have now, not during a drawdown.
- You and your advisor, before the next window: bring the packet above and ask for a gain budget for this tax year, then size the first sale to it. If a vest lands first, the RSU guide covers the withholding side of that event.
How much of one stock is too much?
The common planner threshold is 10 to 15% of investable assets, measured at the household level. Above 30%, it is the dominant fact of your financial life. The threshold matters less than measuring honestly: spouse holdings, ESPP shares, and vested-but-unsold grants all count, and employer stock carries extra weight because your income depends on the same company.
Can I diversify a concentrated stock position without paying capital gains tax?
You can defer or redirect the tax, not delete it. Exchange funds defer the gain for seven-plus years but the basis carries over. Charitable gifts of appreciated shares skip the gain entirely, but the asset goes to charity. Collars protect without selling but suspend holding periods and add cost. Staged selling pays the tax on a schedule you control. Each is worth evaluating with your advisor against your basis and timeline.
What is an exchange fund and what is the catch?
An exchange fund pools appreciated stock from many concentrated investors into one diversified partnership; you swap your shares for units without triggering a sale. The catch is a seven-year lockup, management fees, a required 20% sleeve of illiquid qualifying assets, and the fact that the tax is deferred, not eliminated. Leaving early generally means getting your original shares back.
Does a collar protect my stock without tax consequences?
No. A collar that is too tight can be treated as a constructive sale under Section 1259, taxing you as if you sold. Even a properly sized collar suspends your capital gains holding period and makes dividends non-qualified while it is on. It is a tool for shares you cannot sell yet, sized with professional help, not a permanent tax shelter.
Should I sell my company stock as soon as it vests?
Selling at vest stops the position from rebuilding and adds no extra income tax (the vest itself is taxed either way, as covered in the RSU Vesting Tax Guide). Holding is a decision to buy your employer's stock at today's price. Either can be reasonable; the failure mode is deciding vest by vest. A one-sentence written policy, reviewed annually with your advisor, ends the quarterly debate.
Do I need a 10b5-1 plan to sell as an insider?
A 10b5-1 plan is the standard way for officers, directors, and other insiders to sell on a schedule without trading-window risk. Under current SEC rules, officers and directors face a cooling-off period of at least 90 days (up to 120) before the first trade, and modifications restart the clock, so the plan has to be set up well before the selling needs to start. Whether you need one is a conversation for counsel and your advisor together.
If you only do one thing, compute the household concentration number this week. If it is above 10%, run the Year-End Tax Projection to see how much selling room this tax year has, and bring both numbers to your advisor.
This guide is for planning and coordination only. It does not provide tax, legal, or investment advice. Exchange funds, collars, and charitable structures have eligibility requirements and costs that depend on your full situation; confirm suitability, amounts, and timing with a qualified professional before acting.
