By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.
A time horizon is how long a specific pot of money can stay invested before you need to spend it. It is the single biggest input into how that money should be invested: money needed within about five years usually belongs in cash, Treasury bills or short-term bonds, while money you will not touch for 15 years or more can carry the ups and downs of a mostly stock portfolio.
The mistake high-income families make is not choosing the wrong fund. It is giving the whole balance sheet one horizon. A household with vesting RSUs, a house upgrade in three years, two children under 12 and retirement two decades out has at least five horizons running at once, and each one needs its own answer. For families paid partly in company stock, the horizon of each goal also decides how much of that stock to keep.
Why a family with equity compensation has five different time horizons
Horizon belongs to a goal, not to a person. A 40-year-old physician is not “a long-term investor”. She has an April tax bill that is months away, a down payment that is a few years away, tuition that is 10 to 15 years away, retirement that is 20 or more years away, and money she hopes her children will eventually steward for decades after that.
The SEC’s investor education site defines time horizon as the months, years or decades you plan to invest toward a goal, and notes that investors with a longer horizon may be comfortable with riskier or more volatile investments, while those with a shorter horizon may prefer less volatile ones (Investor.gov, asset allocation). Applied goal by goal, that turns one vague question (“how aggressive should we be?”) into several small, answerable ones.
A worked example: a $950,000 Bay Area household paid partly in RSUs
Assumptions (illustrative): Priya is a scientist at a South San Francisco biotech company and Daniel is a physician. Both are 40, live in California, and have children aged 4 and 7. Household W-2 income is $950,000, of which $300,000 comes from RSUs vesting through the year. They hold about $600,000 of vested company shares, $250,000 in savings, and their 401(k)s.
| Goal | Time horizon | Amount (assumed) | Where it typically sits |
|---|---|---|---|
| April tax balance on RSU income | Under 12 months | $39,000 to $45,000 federal, plus any California shortfall | High-yield savings, money market fund, Treasury bills |
| Emergency reserve | Any time | 6 months of spending, about $150,000 | Cash and Treasury bills |
| Down payment on a larger home | 3 years | $400,000 | Treasury bills or notes laddered to the purchase date, CDs |
| College for two children | 11 and 14 years | Open-ended | 529 plans, age-based portfolios that shift toward bonds as each child nears 18 |
| Retirement or optional work | 15 to 25 years | Open-ended | 401(k), after-tax 401(k) (mega backdoor Roth, if the plan allows), taxable brokerage, diversified stock-heavy mix |
The April tax bill on RSU income is the shortest horizon in the house
Employers commonly withhold federal tax on RSU income at the 22% optional flat rate for supplemental wages, and must withhold 37% on supplemental wages above $1,000,000 in a calendar year (IRS Publication 15, 2026). At this family’s income, most of the $300,000 of RSU income is taxed in the 35% and 37% federal brackets for 2026 (the 37% MFJ bracket starts at $768,700 of taxable income, per Rev. Proc. 2025-32). Withholding at 22% is $66,000. Tax at 35% is $105,000 and at 37% is $111,000, so the federal gap is roughly $39,000 to $45,000. That money has a horizon of a few months, so it usually does not belong in company stock or an index fund.
The down payment is where RSU concentration does the most damage
The couple plans to use $400,000 of their vested shares for the house. Suppose, as a hypothetical, the stock falls 40% over the next two years (single stocks can move far more than the market). The down payment shrinks to $240,000 just as they need it. A three-year horizon cannot absorb a drawdown of that size, and it does not help that the shares are “long-term” in their heads. Moving that $400,000 into Treasury bills or a short Treasury ladder that matures around the purchase date takes the market out of the decision.
The tax cost of that move is often lower than people expect. RSU shares are taxed as wages when they are delivered, and that amount becomes the shares’ cost basis (see “Property Received for Services” in IRS Publication 551). Shares sold soon after vesting usually carry only a small gain or loss. Shares held for years may carry a large one, which is the real trade-off to weigh.
Education and retirement can take market risk
With college 11 and 14 years away, the children’s 529 plans have time to recover from a bad market, and age-based portfolios reduce stock exposure automatically as each child approaches college. For 2026 a parent can use the five-year election to contribute up to $95,000 per child and treat it as spread over five years for gift tax purposes, so a married couple can put up to $190,000 into each child’s 529 at once. The election is made on a gift tax return, Form 709 (Form 709 instructions). Front-loading gives the money the longest possible horizon. California allows no state deduction for 529 contributions, so for this family the benefit is tax-deferred growth and tax-free qualified withdrawals, not an upfront write-off.
Retirement money is the longest horizon they control directly. For 2026 each spouse can defer $24,500 into a 401(k), and total annual additions, including employer money and after-tax contributions, can reach $72,000 per person if the plan allows (IRS Notice 2025-67). This is the bucket where a stock-heavy, diversified mix usually makes the most sense.
How California and Washington change the short-horizon math
California. California taxes all capital gains as ordinary income, with no lower rate for long-term gains (FTB). Holding a stock past one year lowers the federal rate but not the state rate. The top California rate for 2025 is 13.3%: the 12.3% bracket (for joint filers, taxable income above $1,485,906) plus the 1% Behavioral Health Services Tax on taxable income above $1,000,000 (FTB 2025 rate schedules). For short-horizon cash, the interest source matters too: interest on Treasury bills is subject to federal tax but not to state or local income tax (TreasuryDirect). At 2025 state rates of 9.3% to 13.3%, that can make Treasuries more attractive after tax than a bank savings account with a similar posted yield.
Washington. Washington has no wage income tax in 2026, but it taxes long-term capital gains at 7% above an annual standard deduction ($278,000 for 2025, the latest published figure) and, since 2025, at 9.9% on taxable gains above $1,000,000 (WA DOR). Real estate and retirement accounts are exempt. The bigger point for horizon planning: Washington has enacted a 9.9% income tax on individuals and joint filers with adjusted gross income over $1,000,000, starting January 1, 2028 (WA DOR, income tax). DOR has not yet published how income will be calculated or how the new tax will interact with the capital gains tax. A Seattle family with a five-year plan to sell a concentrated position now has a tax rule change inside that horizon, and the order of sales may deserve a second look.
The decision to make, goal by goal
- List every goal with a dollar amount and a date. “Someday” is not a date.
- Sort them into under 1 year, 1 to 5 years, 5 to 15 years and 15 years or more.
- Fund the shortest horizons first, in cash or Treasuries, before adding to long-term accounts.
- Check where company stock sits. Any vested shares earmarked for a goal under five years away are a short-horizon asset held in a single stock.
- Review the map once a year, and after every large vest, bonus, move or new child. Horizons shorten every year whether you act or not.
Common mistakes with time horizons
- Treating vested RSUs as a savings account. They are one company’s stock. If the money has a date attached, it has a horizon, and the horizon usually argues for diversifying.
- Leaving the tax gap uninvested but unlabeled. Families often spend or invest the cash that should cover April. Park it separately so it is still there.
- Using a single risk score for the whole household. A questionnaire that says “moderately aggressive” says nothing about the house fund.
- Letting the 529 drift. If you chose a static portfolio instead of an age-based one, nobody reduces the stock share for you as college approaches.
- Selling everything at once to “de-risk”. In Washington, spreading sales can matter because the capital gains standard deduction is annual. In California, where gains are taxed as ordinary income, a large one-year spike can push more of the gain into the highest state brackets.
What to write down for your children
Children see the house purchase or the paid tuition bill. They rarely see why the down payment sat in Treasury bills while the market was rising, or why their parents sold company stock they believed in. A one-page note per goal (the amount, the date, where the money sits and why) turns an invisible decision into something a teenager can learn from later. As Kevin Luu puts it: “Your kids don’t need to inherit your portfolio. They need to inherit your decision-making process.” This is the kind of entry families keep in a FamilyKnowledge® Library.
Frequently asked questions
What does a 5-year time horizon mean for investing?
It means you expect to spend the money in about five years. That is long enough that holding everything in cash may lose ground to inflation, but short enough that a deep stock market decline may not recover in time. Many families use high-quality bonds, a Treasury ladder or CDs for this bucket, with little or no single-stock exposure.
Does a longer time horizon always mean more stocks?
Usually, but not automatically. A long horizon gives room to recover from declines, yet the family still has to be able to stay invested through them. If a large drop would lead you to sell at the bottom, a slightly lower stock allocation that you actually keep may serve the goal better than a higher one you abandon.
How is account time horizon different from my age?
Age is a rough proxy. Each account has its own horizon set by the goal it funds. A 40-year-old’s 401(k) may have a 25-year horizon, while the same person’s brokerage account holding a house fund has a two-year horizon. Invest each account for its own date.
Next step
Take the five goals above, write a dollar amount and a date next to each, and compare that list with where the money actually sits today. Our investment and risk management and tax management pages explain how an Age Five Family Office™ handles this for families with equity compensation, and related guides cover savings versus brokerage accounts, lump sum versus dollar-cost averaging and family office asset allocation. This is general education, and the right move depends on your family’s full picture.
Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.
Connect on LinkedIn → · About KevinThis is part of how we approach Investment & Risk Management for high-income W-2 families at Bright Advisers.
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