More surface area for profit-seeking.
WHY SHORT-SELLING?
(1) Long-only: the most you can do is not own it. Dislike a company? A long-only manager can lean against it by at most its index weight — leaving it out entirely. For the median Russell 1000 company that is about 0.02% of the index: a view that cannot move the result.
(2) Long/short: room on every name. A manager who can also short it — up to 2% in this illustration — has that room on every company, however small: roughly 89× the median Russell 1000 name's weight.
The index, ranked by weight
Alpha from sell decisions. Short-selling gives a manager far more surface area to act on a negative view, and so far more opportunity to outperform the index with one.
An interactive chart ranks the index by weight: the 25 largest companies as single bars (the largest, 7.3% of the Russell 1000 as of Nov 6, 2026), then one company at every fifth percentile from the 95th down to the 5th — nineteen wider bars, each standing for one company in twenty. Above the baseline, each company's index weight; below it, mirrored, how far a manager can lean against that company: in blue the long-only room, which is the weight itself, and in orange the shorting room, a further 2% under every bar.
The company at the 95th percentile of the Russell 1000 is 0.3% of the index; at the 75th, 0.07%; the median (#503 of 1,005), 0.02%; the 25th, 0.01%; the 5th, 0.005%. Against the median company a long-only manager has 0.02% of room; with shorting, 2.023% — 89× as much. On the Russell 3000 (2,995 companies) the median is 0.003% and the multiple about 740×. A switch picks the index; another picks long-only or long/short; a third expands any one bar to show its figures.
Index weights are computed from the iShares Russell 1000 ETF and Russell 3000 ETF holdings as of Nov 6, 2026, by market value, with Alphabet's two share classes combined; the Russell 3000 fund holds about 2,600 of the index's 2,995 companies, so its lower percentiles are estimates. A 2% maximum short position is illustrative, not a limit of any particular program.
Both sides of a view
Skill pays only where a portfolio can differ from its index — and on most names, long-only leaves almost no room to differ.
Skill needs room. Research into companies only pays where a portfolio can differ from its index. On the long side that difference is capped by each company's weight: a manager who owns none of a company has leaned against it as far as long-only allows. Most of an index is small companies — half the Russell 1000 weighs 0.02% or less — so on most of the names a manager studies, a long-only view is worth almost nothing. Short-selling makes the same view worth up to the short cap, on every one of them.
Pairs and spread. A long/short pair — own the higher-quality company, short the lower-quality one — profits from the gap between them whatever the market does to both. Market exposure is set separately, by how much long and how much short the account carries; tax-aware long/short accounts typically run more long than short, so they keep most of the market's return while adding the spread.
Where the opportunity sits. The chart is the point in one picture: nineteen of its bars are the index from its 95th percentile down to its 5th, and under every one of them the shorting room is the same 2%. Lower-quality companies are not rarer among small names than large ones — if anything the reverse — and short-selling is what lets a view on them count.
What can go wrong
A short position can lose more than it is worth. Sizing, diversification and pairing are the controls; none removes the risk.
Losses have no ceiling. A stock bought can fall to zero and no further; a stock sold short can rise without limit, and every dollar it rises is a dollar lost. A short that doubles against you has cost its whole starting value, and it can keep going.
Borrow, recall and squeeze. Shorting means borrowing the shares. The lender charges for them — a cost that can climb when a name is hard to borrow — and can ask for them back, forcing a position closed at a time not of the manager's choosing. When many managers are short the same company, a rise can force them all to buy back at once, and the rise feeds on itself.
Margin. Short positions live in a margin account, so the whole portfolio stands behind them; a sharp move can bring a call for cash or forced sales elsewhere, and the same borrowing power that makes shorting possible makes leverage available, which magnifies losses as well as gains.
How it is controlled. A cap per name — 2% in this page's illustration — so no single short can hurt much; hundreds of positions on each side, so no one of them decides the result; pairing shorts with longs, so a move in the whole market largely nets out; and daily attention to borrow costs and crowding. These shrink the risk; they do not remove it. Short-selling adds risk of losing money, and it is not for every portfolio.
Tax-inefficient by default, manageable by design
A gain on a short is short-term by law, however long it was held. A tax-aware account sets harvested losses against those gains and defers the long book.
Why shorts are tax-inefficient. A gain on closing a short sale is short-term however long the position was open, so it is taxed as ordinary income — at the top federal rate plus the net investment income tax, rather than the long-term capital gains rate. The dividends a short seller owes the lender of the shares are deductible only within limits. Wash-sale and constructive-sale rules apply to short positions as they do to long ones, and a short against a company the account also owns can trigger a constructive sale of the long. Run without attention to any of this, a short book hands much of its profit to the tax bill.
How it can be managed. In a tax-aware long/short account the short book is one half of a whole. With hundreds of positions on both sides, some always lose, and those losses are realized on purpose and set against the gains — the short book's gains most of all, since they are short-term and the losses harvested against them can be too. Holding periods are watched so gains that can become long-term do; wash-sale and constructive-sale rules are tracked across the whole account; and the long book's appreciation is left to compound and deferred, which is the tax deferral at scale the tax-aware long/short page describes. For the right investor the net effect in most years can be deferral rather than a bill. It depends on the rest of your income and gains, and a tax advisor should look at your situation.