Tailing the Hedge

Tailing the hedge adjusts the futures position downward to account for the time value of daily mark-to-market cash flows. A futures hedge pays or receives variation margin every day, so gains earn interest before they are needed and losses must be funded earlier than under a forward. The naive minimum-variance contract count slightly over-hedges in dollar terms. Multiplying by a tail factor of erTe^{-rT}, or equivalently scaling by the spot-to-futures ratio VA/VFV_A / V_F, removes the bias.

Why it matters

Forwards settle one cash flow at maturity. Futures pay you (or charge you) daily. A futures gain received six months early can be invested and grown at the risk-free rate, so it is worth more than the same gain at maturity. The hedger therefore needs slightly fewer futures than a forward hedge would suggest. The correction is small but matters for institutional hedges running into the hundreds of millions of dollars.

Formulas

Naive hedge contract count
Nnaive=h×QAQFN_{\text{naive}} = h^* \times \frac{Q_A}{Q_F}
Treats futures as if they settled only at maturity, ignoring daily mark-to-market.
Tailed contract count (Hull form)
N=h×VAVFN^* = h^* \times \frac{V_A}{V_F}
VA=St×QAV_A = S_t \times Q_A is the dollar value of the spot exposure and VF=Ft×QFV_F = F_t \times Q_F is the dollar value of one futures contract. The ratio VA/VFV_A / V_F replaces QA/QFQ_A / Q_F and embeds the spot-futures price adjustment. Source: Hull (2022) §3.5.
Continuous-compounding equivalent
NtailedNnaive×erTN^*_{\text{tailed}} \approx N_{\text{naive}} \times e^{-rT}
Holds approximately when SFS \approx F and rr is the risk-free rate over the hedge horizon TT. The two forms agree to first order.

Worked examples

Scenario

A copper smelter has a long hedge with h=0.95h^* = 0.95. Spot copper is US$8,000 per tonne, futures are US$8,080 per tonne, the position size is QA=12,500Q_A = 12{,}500 tonnes, and each LME contract covers QF=25Q_F = 25 tonnes.

Solution

VA=12,500×8,000=V_A = 12{,}500 \times 8{,}000 = US$100,000,000. VF=25×8,080=V_F = 25 \times 8{,}080 = US$202,000. Tailed contracts N=0.95×(100,000,000/202,000)=470.3N^* = 0.95 \times (100{,}000{,}000 / 202{,}000) = 470.3, rounded to 470. The naive count $0.95 \times (12{,}500 / 25) = 475$ would over-hedge by 5 contracts. The tail adjustment is about 1 percent, in line with the rT-rT effect.

Scenario

Naive contract count is 100, risk-free rate r=0.05r = 0.05, hedge horizon T=0.5T = 0.5 years.

Solution

Tail factor erT=e0.025=0.9753e^{-rT} = e^{-0.025} = 0.9753. Tailed contracts Ntailed=100×0.9753=97.53N^*_{\text{tailed}} = 100 \times 0.9753 = 97.53, rounded to 98. The 2 to 3 contract reduction prevents the reinvestment of mark-to-market gains from causing systematic over-hedging.

Common mistakes

  • Tailing produces large changes in contract numbers. The adjustment is typically 1 to 5 percent, depending on rates and horizon. It matters most for large institutional hedges and longer maturities, where small percentages translate into millions of dollars.
  • Tailing applies to forwards as well. Forwards settle once at maturity, so there is no daily mark-to-market to reinvest. The tail adjustment is specific to futures and other daily-settled contracts.
  • The tail factor uses the maturity of the futures contract. The relevant horizon is the hedge horizon TT, that is, how long the hedger expects to hold the position, not the futures expiry. For overnight hedges, the tail effect is negligible.

Revision bullets

  • Adjusts for daily mark-to-market cash flows
  • N=h×VA/VFN^* = h^* \times V_A / V_F in Hull's form
  • Equivalent to multiplying by erTe^{-rT}
  • Reduces the naive futures position
  • Larger effect when rates or horizons are big
  • Does not apply to forwards

Quick check

Tailing the hedge typically results in:

Which of the following best explains why tailing is unnecessary for a forward contract?

Connected topics

In learning paths

Sources

  1. Hull, John C. Options, Futures, and Other Derivatives. 11th ed. Pearson, 2022. ISBN 978-0-13-693997-9.
    Section 3.5 introduces the tailing adjustment, derives the $V_A / V_F$ form, and contrasts the futures hedge with the equivalent forward.
  2. Figlewski, Stephen, Yoram Landskroner, and William L. Silber. Tailing the Hedge: Why and How. Journal of Futures Markets, Vol. 11, No. 2, 1991, pp. 201-212.
    Original article that formalised the tailing adjustment and quantified its impact across different hedge horizons and interest-rate environments.
  3. CME Group. Treasuries Hedging and Risk Management. CME Education Centre, accessed 2026.
    Practitioner reference describing how dealers adjust hedge ratios for daily settlement in interest-rate futures, where tailing is most material.
How to cite this page
Dr. Phil's Quant Lab. (2026). Tailing the Hedge. Derivatives Atlas. https://phucnguyenvan.com/concept/tailing-the-hedge