"Should I sell now, or hold and wait?"

For most families with a brokerage account, the calculator's math reflects what a securities sale actually looks like. The basis returns tax-free, the gain gets taxed, and the after-tax cash is reinvested. The piece the calculator does not see is what is happening across the rest of the portfolio.

Most families with appreciated holdings also have positions trading at a loss. Those losses can be harvested in the same tax year and used to offset the gain. The result is a real reduction in the effective tax that the calculator's flat rate does not capture.

HERE IS THE MATH

Imagine the same $1,000,000 gain from the main scenario. The combined rate is 30 percent, so the calculator shows $300,000 in tax. Now suppose the family also holds a separate position currently sitting on a $250,000 unrealized loss. Selling the appreciated position and the losing position in the same year nets the gain to $750,000. Tax on $750,000 at 30 percent is $225,000. Same sale, $75,000 less in tax.

Excess losses do not disappear. If a family has more loss than gain in a year, the unused portion carries forward indefinitely and can offset gains in future years. Loss carryforwards are an asset on the family's tax balance sheet, and most households underuse them because no one is tracking them.

One other thing the calculator does not address: the wash-sale rule. Under IRC § 1091, selling a security at a loss and buying it (or a substantially identical security) within a 61-day window (30 days before the sale, the day of the sale, and 30 days after) disallows the loss for that year. The disallowed loss is not lost outright; it is added to the basis of the replacement position and recovered on a later sale. The harvesting strategy works only when the family is willing to hold a different but similar position during the wash-sale window, or to wait the full 61 days.

Investment real estate looks like the calculator's framing on the surface. There is a basis. There is appreciation. The gain gets taxed at sale. The thing the calculator cannot see is that the basis of an investment property has been quietly going down for years, because the owner has been claiming depreciation against rental income.

That depreciation is not free. At sale, the IRS recaptures it at a higher rate than the long-term capital gains rate. The result is that two pieces of the same gain get taxed differently, and the calculator's flat rate understates the total tax on a long-held property.

HERE IS THE MATH

Imagine a rental property purchased fifteen years ago for $500,000. Over the holding period, the owner has claimed approximately $200,000 in depreciation (the exact figure depends on the land/building allocation and the depreciation method used), which has reduced the adjusted basis to $300,000. The property is now worth $1,500,000. The total gain at sale is $1,200,000. Two pieces, taxed at two different rates.

The calculator's flat 30 percent rate on a $1,000,000 gain would have shown $300,000 in tax. The actual federal-only tax on this property is $288,000, before any state tax is added. State tax pushes the total higher. The point is not the exact number; it is that the recapture rule changes the math, and the calculator does not see it.

Two other things the calculator does not see for real estate. A §1031 exchange defers the entire gain (recapture and all) if the proceeds are reinvested in qualifying replacement property within the strict identification and timing rules. And if the property is held to death, both the appreciation and the recapture exposure disappear under current basis-step-up rules. For families holding appreciated investment real estate they do not need to liquidate, holding to estate is often the dominant move.

Selling a business looks like the calculator on paper. There is a basis. There is appreciation. The gain gets taxed. What the calculator cannot see is that "selling the business" is not one transaction; it is a negotiated set of choices about what is actually being sold, how the price is allocated, and when the money changes hands. Each of those choices changes the effective tax rate.

The biggest one, especially for a family business worth a few million dollars, is the choice between an asset sale and a stock sale. They produce different tax results for the seller and the buyer, and most actual deals are negotiated on this dimension.

HERE IS THE MATH

Imagine a closely-held business with a basis of $500,000 and a current value of $1,500,000. Same gain as the main scenario. Now imagine two ways the sale can be structured.

The exact number in Structure B depends on how the allocation gets negotiated and what kinds of assets are inside the business. The point of the comparison is that the two structures can move the seller's tax bill by tens of thousands of dollars on a $1.5 million transaction. For larger sales, the swing is larger.

Personal goodwill is the piece that often matters most for personal-services businesses (a CPA practice, a law firm, a medical practice, a financial advisory practice). When the value of the business is tied to the seller personally rather than to the entity, established case law (most notably Martin Ice Cream Co. v. Commissioner, 110 T.C. 189 (1998), and Bross Trucking, Inc. v. Commissioner, T.C. Memo 2014-107) supports allocating part of the price to personal goodwill, taxed as long-term capital gain to the seller. The documentation has to be in place before the sale, not after.

Two other things the calculator does not see. Installment sales spread the gain across the years payments are received, which can keep the seller out of the highest brackets in any single year, with buyer credit risk as the trade-off. And buy-sell agreements often predetermine the terms of any internal sale, which means the agreement itself drives the capital-gains math more than any after-the-fact planning can.

A concentrated single-stock position runs the calculator's math in reverse. Where the basic calculator asks "is the tax savings from waiting worth more than what we lose by leaving the money tied up," a concentrated position adds a second question: "is the tax savings from waiting worth more than what we could lose if the stock drops while we wait."

That second question is the one most families never put on paper. They feel the tax cost clearly because the dollar amount is concrete. They feel the concentration risk vaguely because it is not a number on any statement.

HERE IS THE MATH

Imagine the same $500,000 basis and $1,500,000 current value from the main scenario, but in a single employer stock. Selling now triggers $300,000 in tax. Holding to defer the tax feels like saving $300,000. Now suppose the stock drops 30 percent during the holding period, which is well within the historical range for any single stock.

The family that sold and diversified is up $150,000 against the family that held. The tax savings became irrelevant the moment the stock moved. The point is not that concentrated stocks always drop. The point is that the tax savings from waiting is a small number compared to the range of outcomes a single stock can produce in five years.

For positions large enough to justify the complexity, exchange funds are a specialized tool worth knowing about. The investor contributes the concentrated position to a pooled fund alongside other investors with their own concentrated positions, receives a diversified interest in the pool, and defers the gain until the position is eventually liquidated. Holding requirements are typically seven years.

For positions held long enough to anticipate passing through the estate, the basis step-up at death applies the same way it does for any other appreciated asset. That changes the calculation entirely. For positions held in retirement accounts, the analysis is different again (no capital gains treatment at all; distributions are ordinary income).

Equity compensation does not fit the calculator's framing the way the other asset types do. The calculator assumes there is a basis, a current value, and a single decision point about when to sell. Equity compensation has at least three decision points (grant, vesting, exercise) and the tax consequences fall at different ones depending on the type of grant.

The result is that the planning conversation for equity compensation looks different. It is less about "when do we sell" and more about "how do we coordinate vesting, exercise, and sale across multiple years to keep the family out of the highest brackets in any single year." For executives subject to trading windows, 10b5-1 plans add another layer. For founders and early employees with restricted stock granted at low value, §83(b) elections are a real planning lever that has to be made within thirty days of grant or it is gone.

Collectibles look like the calculator on the surface but run on a different federal rate. The long-term capital gains rate that most families think of as 20 percent is actually a maximum rate, and Congress wrote a higher one into the Internal Revenue Code specifically for collectibles. The calculator's 30 percent default rate, which combines the federal long-term rate with the 3.8 percent NIIT and a typical state rate, understates the tax on a collectibles sale by roughly eight percentage points.

HERE IS THE MATH

Imagine the same $1,000,000 gain from the main scenario, but now the asset is a piece of art rather than a stock. The calculator's flat 30 percent rate would show $300,000 in tax. The actual rate on a collectibles sale runs higher.

A note on the Massachusetts rate: Massachusetts taxes long-term collectibles gains at a 12 percent statutory rate with a 50 percent deduction, producing a 6 percent effective rate. The 4 percent millionaires surtax under M.G.L. c. 62 § 4(d) stacks on top of that effective rate when applicable. Connecticut applies its top marginal rate of 6.99 percent. The values above update when you select your state above.

If you are running a collectibles scenario in the calculator, move the "today's tax rate" slider to 37.8 percent before drawing any conclusions. The numbers behave correctly once the rate is right; the default is wrong for this asset type.

Two other things specific to collectibles. The basis-step-up at death applies the same way for tangible assets as for financial assets, but valuation can be more contested with the IRS, particularly for art and other items without clear market comparables. Get a current appraisal before any planning conversation, because for items held for decades the basis question is often unclear.

Charitable giving with collectibles also has its own rules. A donation of appreciated collectibles to a public charity is generally deductible at fair market value if the charity uses the item for its exempt purpose (a painting donated to a museum that displays it). Otherwise the deduction is limited to basis (a painting donated to a hospital that auctions it for cash). This makes charitable planning with collectibles substantially more complex than with publicly-traded securities.

For tax purposes, the IRS treats cryptocurrency as property, not currency. Long-term gains (held more than a year) are taxed at the same federal rates as long-term stock gains, plus NIIT and state. On the headline rate, the calculator's framing applies cleanly. The reason cryptocurrency does not fit the rest of the calculator's framework comes from the surrounding facts, not from the rates.

Where the planning conversation lands depends entirely on the family's situation. A modest holding with clear basis records on a single exchange runs almost like a stock position. A larger holding accumulated across multiple platforms over years, with the family member who manages it as the only person who knows the access details, is a different conversation that combines tax planning, estate administration, and operational security.