Net exposure subtracts short exposure from long exposure. A USD 1 million equity ledger shows what 40% net reveals—and what a zero-net book can still lose.
Net exposure
Net exposure is long exposure minus short exposure, measured on a stated basis. For a cash-equity long–short portfolio, it is the market value of long shares less the positive market-value magnitude of short shares, often divided by net asset value (NAV). It shows the book’s signed dollar imbalance: a portfolio can carry large positions on both sides while reporting a small net number.
The Janus Henderson glossary uses this long-minus-short convention. Here the denominator is positive NAV at the same valuation time, and cash is excluded from the equity-exposure numerator.
A 40% net book, reconciled
Consider a synthetic account at the beginning of a month. It owns one equity basket and shorts a different basket, with no overlapping positions. Write L for long market value and S for the positive magnitude of the short liability.
Opening balance sheet
USD
Long shares, L
1,200,000
Cash, C
600,000
Shares owed to the lender, −S
−800,000
NAV, E=L+C−S
1,000,000
Short selling produces cash and an obligation to return the borrowed shares. The USD 800,000 of proceeds does not add USD 800,000 to equity: it is offset by the short liability. Initial capital of USD 1,000,000, less the USD 1,200,000 long purchase, plus the USD 800,000 short sale leaves the USD 600,000 cash balance.
This simplified balance sheet assumes a financing arrangement permits the positions without another borrowing liability. The cash balance is an accounting asset; it is not a statement of free margin or withdrawable funds. Short proceeds and other cash may be restricted as collateral. The SEC’s introduction to short sales explains the borrowing obligation and margin mechanics.
The net dollar exposure is USD 400,000. As a fraction of NAV,
N=EL−S=1,000,0001,200,000−800,000=40%.
Equivalently, the signed equity weights are +120% long and −80% short. Gross exposure adds their magnitudes, giving 200%. Cash enters NAV through the balance sheet; dividing USD 400,000 by USD 600,000 of cash would produce a different measure.
What cancels under a common move
Keep the share quantities fixed for the month. Ignore distributions, stock-borrow fees, financing, trading costs and cash interest. If both baskets’ prices rise by exactly 10%, the long gains USD 120,000 and the short loses USD 80,000. Price-only profit and loss is USD 40,000, or 4% of initial NAV. Closing NAV is USD 1,040,000.
For a common price return r, the cancellation is exact under these assumptions:
EΠprice=ELr−Sr=Nr.
Thus 40%×10%=4%. Net exposure is useful for this deliberately identical shock. It does not predict that two different baskets will move together or estimate their response to a market index.
Two synthetic USD 1 million NAV books both have 200% gross exposure. USD 1.2 million long less USD 0.8 million short gives 40% net and USD 40,000 gain under a common 10% price rise. USD 1 million on each side gives zero net and zero common-shock price gain.
Original synthetic cash-equity comparison. Values and price P&L are in USD; each book starts with USD 1 million NAV. Fixed holdings, identical +10% basket price shocks, no costs, distributions or cash interest.
A zero is a constraint, not a risk verdict
Compare a second book with the same USD 1,000,000 NAV, USD 1,000,000 long and USD 1,000,000 short. Its simplified cash balance is USD 1,000,000. It also has 200% gross exposure, but its net exposure is zero: it is dollar-neutral. The identical +10% price shock makes USD 100,000 on the long and loses USD 100,000 on the short, for zero price P&L.
Now let the long basket rise 5% while the shorted basket rises 10%. The same zero-net book loses USD 50,000, or 5% of initial NAV. The shorted basket’s return is the return of the shares themselves; a rise hurts the short position. Dollar cancellation has not cancelled relative-performance risk.
Nor does equal dollar size establish beta neutrality. If the two baskets have different market betas, their market sensitivities need not offset. Sector and style factor exposures, differences between the hedge and the assets being hedged, individual-company shocks and liquidity risk remain. Borrow recalls, fees and funding demands can also change the outcome. Net exposure is one coordinate in a risk report.
Constrained factor portfolios takes this distinction into portfolio construction: net and gross position sizes, holding caps and factor neutrality impose different restrictions. The lesson has a public preview; full access requires membership.
Before comparing reported net exposures, check the assets included, valuation time, netting level and denominator. A negative net number means the short magnitude exceeds the long under the stated convention. For derivatives, the chosen measure may use notional or a sensitivity adjustment rather than market value. A net number without its measurement basis is incomplete.
Qian, Hua and Sorensen, Quantitative Equity Portfolio Management: Modern Techniques and Applications (Chapman & Hall/CRC, 2007), §11.3.1, pp. 374–375. Signed sizing, long-plus-short exposure and financing mechanics.
