Is there a hard percentage rule for how concentrated is "too concentrated"?

No official rule exists, but many financial planners treat 10-15% of net worth in a single employer's stock as a level worth actively managing down. Your own comfort level and job security matter too.

Does this framework apply the same way to ISOs and NSOs?

The concentration and time-value logic applies to both. The tax mechanics differ — ISOs can trigger AMT and offer long-term capital gains treatment if holding periods are met, while NSOs are taxed as ordinary income at exercise regardless of holding period. See our ISO vs. NSO tax differences guide.

What if my company is still private — does "time value" still apply?

Yes, the same intuition holds, but private companies add liquidity risk on top of time value, since you generally can't sell shares until a later event like an IPO or acquisition. See should you exercise before an IPO for that specific case.

Should I exercise all my in-the-money options at once for simplicity?

Not necessarily. Exercising in stages lets you manage the tax bill (especially AMT on ISOs) and cash outlay across multiple years rather than all at once. Prioritize by concentration risk and remaining time value, as in the Marcus example above.

Does the $100,000 ISO limit affect exercise timing?

It can. Only the first $100,000 in value (based on grant-date fair market value) of ISOs that first become exercisable in a calendar year can be treated as ISOs; the excess is treated as NSOs. See our $100k rule explainer for how this interacts with multiple grants vesting in the same year.

When should I exercise my stock options?

There's no single rule for when to exercise stock options. It depends on concentration, remaining time value, and your cash-flow needs.

There's no single rule that tells you when to exercise stock options. The right timing depends on three things: how much of your net worth is already tied up in your company's stock, how much "time value" your options still have left to run, and how soon you'll need the cash. Options that are deep in the money with little time left have the weakest case for waiting; everything else is a judgment call.

Marcus has been at the same mid-size tech company for seven years and has four separate option grants sitting in his account, all vested, none exercised. Some are barely in the money, one is worth ten times its strike price. He keeps meaning to "deal with the options" but has no idea which ones to touch first, so he's touched none of them.

Key points

There's no universal exercise rule — the right answer depends on your concentration in company stock, the remaining time value of each grant, and your cash-flow needs.
Time value is the value of the right to keep waiting. Deep in-the-money options with little time left have burned through most of that value, so there's less reason to keep holding them unexercised.
When you hold multiple grants, exercise the ones with the least remaining time value and the highest concentration risk first — not necessarily the ones with the biggest dollar spread.

Why "just wait" isn't always the right answer

An option gives you two things at once: the value you'd capture if you exercised today (the "in-the-money" value, or spread), and the value of being allowed to keep waiting instead (the "time value"). Both matter, and confusing them is why exercise timing feels so hard.

Think about it this way. If your strike price is $10 and the stock is at $40, exercising today locks in a $30-per-share gain. But if you wait, the stock could go to $60, and you'd have made $50 instead — the option to wait is itself valuable, because you're not risking anything by continuing to hold an unexercised option (you can only lose what you'd have paid to exercise, not more). That's the same logic that makes any option valuable: the right to decide later, once you know more, is worth something.

The catch is that this "value of waiting" isn't constant. It shrinks as the option gets closer to its expiration date, and it shrinks as the option gets deeper in the money. An option that's already worth 10 times its strike price with two years left on a ten-year term has captured most of the gain a typical option can realistically capture — there just isn't that much more "waiting value" left to lose by exercising now. An option that's only slightly in the money with eight years left on its term still has a lot of room left to run, so cashing out early gives up more.

You don't need to run a Black-Scholes model to use this intuition. As a rough guide: the bigger the spread relative to the strike price, and the less time left before expiration, the weaker the case for continuing to hold an unexercised option instead of exercising (and, if diversification is a goal, selling).

Factor 1: how concentrated is your net worth in company stock?

Add up your unexercised options, any vested RSUs or restricted stock, ESPP shares, and anything else tied to your employer's stock price. If that total is a large share of your net worth, you're carrying concentration risk on top of the normal risk of holding any single stock — and you're also depending on the same company for your paycheck.

Many financial planners get uncomfortable once company stock and options exceed roughly 10-15% of someone's total investable assets, because a single bad year at one company can hit your net worth and your income at the same time. There's no legal threshold here, just a risk-management guideline — but it's a useful gut check when deciding whether to exercise and diversify versus keep holding.

Factor 2: how much time value is left on the option?

This is the piece most people skip. Two options can have the exact same dollar spread today and still deserve completely different treatment, because one has years of runway left and the other is close to expiring.

As a practical shortcut, ask two questions about each grant: how many years are left until expiration (most options have a 10-year term from grant), and how far in the money is it relative to the strike price? A grant that's deep in the money with only a year or two left has little time value left to protect by waiting — exercising doesn't cost you much optionality you weren't already about to lose. A grant that's only modestly in the money with six or seven years left still has real time value, and cashing it out early gives up more of what makes options valuable in the first place.

Factor 3: your cash-flow needs and risk tolerance

The more time you have before you need to fund something big — a house down payment, tuition, retirement — the more room you have to let options run and let time value keep working for you. If you need cash soon, or you simply can't stomach watching a large paper gain evaporate, that argues for exercising (and often selling) sooner, even if it means giving up some theoretical upside.

There's also a practical tax angle for ISOs: exercising and holding shares for more than one year after exercise and more than two years after grant qualifies the eventual gain for long-term capital gains treatment instead of ordinary income rates (IRS Topic 427). If you're planning to exercise eventually anyway, doing it earlier — while the spread and any AMT exposure are smaller — can start that clock sooner. See our guide to exercising before an IPO for how this plays out at a private company specifically; this page is about the general framework that applies at any stage, public or private.

A worked example: Marcus and his four grants

Marcus, 34, works at a public tech company and has four vested option grants, all with 10-year terms. Current stock price: $52.

Grant	Strike	Years left	Spread per share	Rough time value left
A	$8	1.5	$44	Very low — deep in the money, little runway
B	$30	3	$22	Low-moderate
C	$45	7	$7	High — barely in the money, lots of runway
D	$48	8	$4	High — near the money, long runway

Marcus also has $180,000 of unvested RSUs and a $90,000 brokerage account with no company stock. His company stock and options add up to roughly 55% of his total investable assets — well above the 10-15% concentration guideline, which tells him diversification should be a priority, not just an afterthought.

Applying the framework: Grant A is the clearest candidate to exercise first. It's deep in the money ($44 of spread on an $8 strike) and has only 18 months left before expiration, so there's very little time value left to protect. Grant B is next — still meaningful spread, but more room left on the clock, so it's a reasonable second move rather than an emergency.

Grants C and D are the opposite case. They're only modestly in the money relative to their strike prices, and they have 7-8 years left to run. Exercising them now would convert a large amount of remaining time value into a much smaller locked-in gain, for comparatively little concentration benefit today (the dollar spread is small). Marcus is better off leaving C and D alone for now and revisiting them as they get closer to expiration or deeper in the money.

Marcus decides to exercise Grant A in full, using part of the proceeds to cover the exercise cost and taxes, and to revisit Grant B within the next year. He leaves C and D as they are.

How WealthOS helps

Connect your grant details in WealthOS and we'll calculate the concentration and remaining-runway picture across all of your grants automatically, so you can see which ones look like Marcus's Grant A versus his Grant C without building the table yourself.

Frequently asked questions

Is there a hard percentage rule for how concentrated is "too concentrated"?: No official rule exists, but many financial planners treat 10-15% of net worth in a single employer's stock as a level worth actively managing down. Your own comfort level and job security matter too.
Does this framework apply the same way to ISOs and NSOs?: The concentration and time-value logic applies to both. The tax mechanics differ — ISOs can trigger AMT and offer long-term capital gains treatment if holding periods are met, while NSOs are taxed as ordinary income at exercise regardless of holding period. See our ISO vs. NSO tax differences guide.
What if my company is still private — does "time value" still apply?: Yes, the same intuition holds, but private companies add liquidity risk on top of time value, since you generally can't sell shares until a later event like an IPO or acquisition. See should you exercise before an IPO for that specific case.
Should I exercise all my in-the-money options at once for simplicity?: Not necessarily. Exercising in stages lets you manage the tax bill (especially AMT on ISOs) and cash outlay across multiple years rather than all at once. Prioritize by concentration risk and remaining time value, as in the Marcus example above.
Does the $100,000 ISO limit affect exercise timing?: It can. Only the first $100,000 in value (based on grant-date fair market value) of ISOs that first become exercisable in a calendar year can be treated as ISOs; the excess is treated as NSOs. See our $100k rule explainer for how this interacts with multiple grants vesting in the same year.

Sources

This article is educational and not tax, legal, or financial advice. Talk to a CPA or tax advisor about your specific situation.

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