The pattern is familiar to anyone who works with founders, early employees, or long-term investors. A single position, often acquired at a very low cost basis, has grown to represent half or more of a family's net worth. The textbook answer is to diversify, but the textbook answer ignores the tax. Selling a $10M position with negligible basis generates roughly 37% in combined federal and state tax for a high earner in a high-tax state, about $3.7M, plus the loss of everything those dollars would have compounded into over the following decades.1
Faced with a choice between concentrated risk and an immediate seven-figure tax bill, most investors choose neither. They hold the position, revisit the question periodically, and take no action. Doing nothing appears to be the conservative option. It is actually a large, unhedged bet that one particular company will keep performing indefinitely.
Why holding is riskier than it feels
An index fund is self-correcting in a way a single position is not. When a company inside the index declines, its weight shrinks and stronger companies replace it, which is why an index can compound for a century while most of its original members disappear. A single stock has no such mechanism. The history of individual companies, including dominant and seemingly permanent ones, is largely a history of eventual disruption, and most investors can name a company once considered untouchable that later lost half its value and never recovered it.
There is also an asymmetry that matters more than the statistics. Once a position is large enough to secure a family's future, the remaining upside is worth less than the equivalent downside costs. If the position doubles again, little changes. If it falls 60%, a great deal changes. That is a statement about utility more than a market forecast, and it argues for reducing the position at almost any reasonable price.
The conventional tools
The wealth management industry offers a familiar set of tools, and each addresses a piece of the problem while leaving the core intact.
Selling outright removes the risk and maximizes the tax. Exchange funds pool the stock with other investors' concentrated positions, which diversifies without a sale, but they generally require multi-year lockups, charge meaningful fees, and leave the investor fully exposed to equities throughout.
Collars can limit the downside, but hedging costs money, tax rules restrict how tightly a position can be hedged without triggering a constructive sale, and the embedded tax bill is still waiting at the end. Borrowing against the position raises cash without a sale, but it layers leverage onto an already concentrated portfolio. Charitable vehicles work well for the portion an investor intends to give away, but they do nothing for the portion the investor intends to keep.
None of the conventional tools create the capacity to actually sell the position down. That is the specific gap tax-aware long/short strategies address.
Building the capacity to sell
A tax-aware long/short strategy adds a model-driven book of short positions on top of a diversified long portfolio.2 In any given year some longs fall and some shorts rise, and each of those positions can be sold and realized as a loss. In our simulations over the last ten and a half years of market data, a 150/50 portfolio realizes net losses of 20% to 30% of portfolio value in a typical year, with cumulative losses passing 100% of invested capital around the third year.3
Realized losses carry forward indefinitely, so they accumulate into a loss base that can be applied against future gains. Against a concentrated position, that base is what makes a sale affordable. Each dollar of accumulated losses allows a dollar of appreciated stock to be sold with the gain fully offset, deferring the tax that made diversification appear too expensive.
Consider an investor with a $10M concentrated position and $5M of other liquid assets. The $5M funds a tax-aware long/short program. At the loss generation rates our simulations suggest, the program accumulates something on the order of $5M in realized losses within roughly three years. The investor can then sell half the concentrated position with no current tax due, and the proceeds move into the diversified program, where they generate further losses for the next stage. A decision that was unworkable as a single transaction becomes a manageable multi-year plan.
There is a further benefit while the program runs. The program capital is a diversified investment seeking returns of its own, so the family's overall risk profile begins improving from the first year, well before the position is fully unwound. The strategy diversifies, pursues return, and builds tax capacity at the same time, which is why it fits this problem better than tools that do only one of the three.
What it doesn't do
The approach has limits, and they are worth stating plainly. The losses defer tax rather than eliminate it. The deferred gains come due if the diversified portfolio is eventually liquidated, although deferral itself has value the research literature has documented for decades,4 and positions held until death currently pass to heirs with the basis reset. Building a meaningful loss base takes time, so the strategy suits investors who can commit to a multi-year plan. It involves shorting, leverage, and tracking error against the index, which require institutional infrastructure and a manager with genuine long/short experience. And the portfolio has to make sense as an investment on its own merits, because tax law's economic substance doctrine disallows arrangements whose only purpose is their tax treatment.
The takeaway
The concentrated stock problem persists because both obvious answers are unattractive. Selling surrenders a substantial share of the position to taxes, and holding leaves a family's financial security dependent on one company's next decade. Tax-aware long/short strategies offer a third answer, which is to build the tax capacity to sell over several years and then sell the position down in stages. The investors with regrets tend to be the ones who waited for a better option that never arrived.