Long Strangle
Prerequisite strategies: the long call and long put, traded to a written plan and held through at least one full expiry cycle, plus the long straddle so that you have felt what you are paying for. Clear the Level 2 gate first. Next: the calendar spread; the more precise version of this idea is the backspread.
Why this structure exists
Level 2's organising idea is that risk is fixed by construction rather than by collateral: in every credit spread in this tier the worst case is width minus credit, a number set by the strikes you picked and not by cash the broker rings off. The long strangle is the purest case of that idea and the one exception to the formula. There is no width and no credit — both legs are bought, so the maximum loss is the debit, known to the penny before you click, and no market can produce a worse number.
What it buys is exposure to the size of a move rather than its direction. A long call needs the index up and a long put needs it down; a strangle needs it to go somewhere. That is the trade when you can date a catalyst but not call it — a Bank of England decision, an index review, a results day — and it is only worth taking when implied volatility is cheap, because what the chain charges for movement is the whole price of the position.
The nearest simpler alternative is the long straddle: same two legs, both struck at the money. Why not just do that instead? Because the straddle below costs £3,513.61 against this structure's £1,306.46 — 2.69 times the money to bring the breakeven 18.4% nearer, which is the same arithmetic read the other way: this structure needs a move 22.6% larger. Take the straddle when you want the highest chance of any profit, the strangle when the capital saved is what lets you size the trade to survive being wrong. Be honest about which is true, because cheapness is why people buy too many of these.
Construction
| Leg | Buy / Sell | Quantity | Strike rule | Expiry rule | Target delta | Price |
|---|---|---|---|---|---|---|
| Put | BUY (debit) | 1 contract = £10 per index point | First listed strike at or beyond 25 delta below spot | 45–90 DTE, and the catalyst must fall inside it | −0.23 to −0.27 | 61.62 pts = £616.23 |
| Call | BUY (debit) | 1 contract, same expiry | First listed strike at or beyond 25 delta above spot | Same expiry as the put | +0.23 to +0.27 | 69.02 pts = £690.24 |
| NET | Net debit | 1 strangle | 8,700 put / 9,300 call, 9,000 spot | 45 days | +0.03 (+£0.31/pt) | 130.65 pts = £1,306.46 |
ICE lists FTSE 100 exercise prices in intervals of 25, 50, 100 or 200 points, so the 25-delta strikes round to 8,700 and 9,300. Three hard inequalities decide whether the strikes are right, and the first is the whole strategy:
Formulas: max loss = (put premium + call premium) × multiplier + opening costs, suffered at any settlement between the strikes. Breakevens = put strike − total debit, call strike + total debit. Max profit is uncapped above the upper breakeven and runs to (put strike − total debit) × multiplier below the lower one.
The shaded band is the move the chain is pricing; the breakevens sit just inside its edges, at 0.973 SD. That is the strike-selection rule made visible — widen the strikes and the breakeven lines slide outside the band. The dashed line is the position today: far above the expiry floor in the middle, because everything you own is time value, and converging with it in the tails. On the extreme left it dips a shade below the expiry line, because a deep in-the-money European put is worth marginally less than its intrinsic value until settlement and cannot be exercised early to capture the difference.
Entry criteria
| Gate | Rule | Reason |
|---|---|---|
| IV rank / percentile | IVR below 25 and IV percentile below 30. Below 15 is better. Hard stop at IVR 40 | You are long £199.33 of vega. IV 14% in a 52-week range of 11–36% is IV rank 12. The same strikes at IVR 60 cost £3,967.94 and need a 1.618× larger move |
| Term structure | Front month at or below the second month | Backwardation means you are buying the dear end of the curve; you want the cheap end, with the catalyst inside it |
| Days to expiry | 45–90, closed at 21 | Theta costs 2.37% of the position's value per day at 45 DTE and 6.41% at 22 DTE. The last three weeks are paid-for risk you no longer own |
| Strikes | 25 delta each side, both listed, both breakevens inside ±1 SD | At 16 delta the breakevens fall outside the expected move. The debit gets smaller and the trade gets worse |
| Liquidity | Spread ≤ 8% of the strangle mid; open interest ≥ 250 on both legs | You pay the spread twice on two legs. ICE UK single-stock series routinely quote 10% wide, which is 10% of the debit gone before the index moves |
| Underlying | A realised-volatility history that actually delivers moves of this size | An index that has not travelled 4.8% in 45 days for two years is not going to start because you bought a strangle |
| Event calendar | A dated catalyst inside the window — MPC, CPI, index review, results — and volatility not yet bid for it | The event is the thesis. If the chain has already repriced for it, you are buying the answer |
Do not enter if: IV rank is at or above 40 — this is the case where volatility itself says no, and it is the commonest way to lose money while being right about the move; the debit exceeds 2% of the account; either breakeven sits beyond 1 standard deviation; results or a rate decision land after your expiry rather than inside it; or the round-trip spread on the two legs exceeds 8% of the debit.
Credit or debit — the same view, two prices
This structure is a debit: you pay £1,306.46 for the right to be paid for movement. The same long-gamma view can be financed instead. A call backspread — sell one 9,150 call at 114.46 points, buy two 9,400 calls at 47.55 — comes in for a net credit of £193.56, so a market that goes nowhere pays you rather than costing you the debit. The bill arrives elsewhere: a £2,306.44 loss valley at 9,400, an upper breakeven at 9,630.64 (+7.01% against the strangle's +4.78%), and no participation at all if the index falls. The rule is arithmetic, not taste. Buy the strangle when IV rank is below 25 and you want both directions; finance it as a backspread when IV rank is high enough that buying two options outright is unaffordable and you are willing to give up one side.
Greeks at entry and how they evolve
| Greek | Entry — 45 DTE, 9,000, IV 14% | 22 DTE, unchanged | 7 DTE, unchanged | +1 SD (9,442.4), IV 12.5%, 30 DTE | −1 SD (8,557.6), IV 18%, 30 DTE |
|---|---|---|---|---|---|
| Delta (£ per point) | +0.31 | +0.21 | +0.08 | +6.63 | −5.54 |
| Gamma (£/pt per 100 pts) | +1.43 | +1.61 | +1.04 | +1.14 | +1.12 |
| Theta (£ per day) | −30.90 | −34.93 | −22.69 | −22.40 | −35.59 |
| Vega (£ per vol point) | +199.33 | +109.88 | +22.69 | +104.56 | +121.76 |
| Position mark | £1,306.46 | £544.96 | £61.00 | £2,201.33 | £2,653.96 |
Black–Scholes, 4% rates, 3.5% index dividend yield, per one £10-a-point contract. Implied volatility is stepped down on up moves and up on down moves to reflect equity index skew, which is why the −1 SD column marks £452.63 higher than the +1 SD column at the same distance.
Vega decides whether this trade wins; theta decides what waiting costs. At entry one implied-volatility point is worth £202.41 to you against £101.28 for a 100-point index move — so for the first fortnight this is a volatility position wearing a directional costume, which is exactly why the entry gate is set on IV rank. The character then flips twice. First around 21 days, when theta becomes the dominant term: the burn is 2.37% of remaining value per day at 45 DTE, 6.41% at 22 DTE and 37.20% at 7 DTE. Second at the strikes, because your long gamma only exists near them — standing at 9,000 with 7 days left you hold £61.00 of gamma nobody wants, while at the 9,300 call gamma is +£2.22 per point per 100 points at 7 DTE and +£4.14 at 2 DTE. Long gamma is not a property of the position; it is a property of where the index happens to be standing.
FTSE 100 at 9,000, implied volatility 14%, IV rank 12, 45 days to run
The ICE FTSE 100 index option is worth £10 per index point (£90,000 of notional at 9,000), is European style, settles in cash against the Exchange Delivery Settlement Price, ticks in 0.5 points (£5), trades 08:00–16:50 London, and on the third Friday stops trading as soon as reasonably practicable after 10:15. One standard deviation over 45 days at 14% is 442.42 points.
The trade: buy 1 × FTSE 100 8,700 put and 1 × FTSE 100 9,300 call, same expiry.
Branch A — the target fires. FTSE 9,380 (+4.22%) at 30 DTE, volatility flat.
Branch B — the crash. FTSE 8,350 (−7.22%) at 20 DTE, IV up to 24%. Move and volatility arrive together, which is why the put side pays more than the call side ever will.
Branch C — right on direction, still losing. FTSE 9,150 (+1.67%) at 24 DTE, IV crushed from 14% to 11%.
Branch D — nothing happens. FTSE 9,000 at 25 DTE. Twenty calendar days after entry the strangle marks £649.37, so the −50% stop fires four days before the 21-day time stop: sell for £645.37, realising −£665.09. Ignore the stop and at 21 DTE the mark is £510.01 and the loss −£804.45.
Branch E — held to settlement at an EDSP of 9,000. Both legs lapse and the full £1,310.46 is gone, an allowable capital loss for 2026/27. Cash settlement means no delivery, no assignment notice and no stamp duty.
On an ICE UK single stock instead the size problem inverts and a new one appears. A BP strangle at 530p, 45 days, 26% implied volatility and a 5% dividend yield — the 500 put at 7.57p (delta −0.250) and the 570 call at 5.88p (delta +0.221) — costs 13.45p × 1,000 shares = £134.51, a tenth of the index version and affordable on a £10,000 account. But the breakevens are 486.55p and 583.45p, needing 8.2% down or 10.1% up, and a 10% bid-ask — normal on a thin UK chain — costs £13.45 round-trip, exactly 10% of the debit. The series are physically delivered and American style, so an in-the-money leg left to expire is exercised: the 570 call delivers 1,000 shares for £5,700 plus £28.50 of SDRT, and the 500 put obliges you to deliver 1,000 shares you may not own.
On a US underlying the gain is computed in sterling on each disposal date. A $1,400 debit at GBP/USD 1.3552 costs £1,033.06; closing for $2,100 at 1.4000 returns £1,500.00. Dollar profit 50.0%, sterling profit £466.94 or 45.2% — £49.59 less than an unchanged rate would have given, before the broker's conversion spread on both legs.
This is a single, hand-picked, favourable scenario. It is not a typical or expected outcome. Every premium is modelled from Black–Scholes at the stated inputs rather than taken from a live chain, and 9,000 is an illustrative round number. Real fills are worse, and a modelled 33.0% probability of finishing beyond a breakeven means two trades in three end at or near the maximum loss. Past performance, including any illustrative example shown here, is not a reliable indicator of future results.
Management and adjustment
| Trigger | Diagnosis | Action | Do NOT do this |
|---|---|---|---|
| One leg reaches 3× its cost | The move arrived; the position is now directional, not neutral | Leg out. Sell the winner, keep the loser as a free option. Branch B banks £2,810.07 and keeps the call | Hold both legs hoping the index reverses back through your other strike. It has to travel 861 points to pay you twice |
| IV rank expands above 40 with the index still inside the band | The vega gift arrived without the move | Take it. Close for whatever the vol repricing is worth — a 6-point IV rise at 38 DTE marks the position at £2,230.08, a £915.61 profit on a motionless index | Wait for the move as well. You were paid for the thing you bought |
| IV rank collapses after entry | IV crush. The thesis is dead regardless of direction | CLOSE. Branch C: −£815.23 with the index up 1.67% | Wait for the move to rescue the vol loss. It needs a bigger move than you underwrote |
| The catalyst passes with no move | You own decay and nothing else | CLOSE the next morning, whatever the P&L | Keep it "in case". The reason you bought it has already happened |
| 21 days to expiry reached, index inside the band | Theta is now 6.4% of remaining value per day and your gamma is nowhere near a strike | CLOSE. Time stop, not negotiable | Hold for the last three weeks. On a motionless index that surrenders the remaining £510.01 — 39% of the original debit |
| Index drifts to one strike with more than 21 DTE left | Gamma is now working; the position is worth more than the model's mid | Hold, and move the profit target to the mark. Gamma at a tested strike doubles between 45 and 7 DTE | Roll the untested leg closer to "balance the deltas". You would be paying a fresh debit to raise your own breakeven |
| A new dated catalyst appears beyond your expiry | Right idea, wrong contract month | Close, then reopen in the later month only if the new debit passes the roll test below | Treat it as an adjustment. It is two trades and a second maximum loss |
ROLL WHEN the thesis is intact, the catalyst has genuinely moved beyond your expiry, and the replacement debit is no more than 50% of the original — because your total risk on the idea is the money already lost plus the new debit. ROLL TO the next monthly at fresh 25-delta strikes, as two separate orders, logged as a new trade with its own maximum loss and stop. DO NOT ROLL otherwise, and here is the arithmetic that makes that a rule rather than an opinion: at 21 DTE with the index at 9,000 you close for £510.01, having lost £804.45, and the 60-day replacement at 8,700 / 9,350 costs £1,619.55 against a 50% test of £655.23. It fails. Roll anyway and your total exposure to one unchanged opinion is £2,428.00, 1.85 times the maximum loss you agreed to when you sized the trade. The credit trader's rule is never roll for a net debit; the debit trader's is never roll for a debit that takes cumulative risk above the number you wrote down. The correct action is to CLOSE whenever the stop or time stop has fired, whenever IV rank has risen above 40 so the replacement would be bought expensive, or whenever the catalyst has already happened.
Exit rules
If all four are silent, do nothing and check IV rank tomorrow. "Nothing" costs £30.90 a day.
Margin and broker reality
Here is the tier's most useful sentence, and the exception to it. A margin account, not a cash account, is required for a spread — spread positions and uncovered writing cannot be held in a cash account, which is the commonest reason a UK reader's first credit-spread order is rejected. The long strangle is the exception: both legs are bought and fully paid, so there is no margin requirement at all. Initial £1,310.46, maintenance £1,310.46, buying-power reduction £1,310.46. It never rises, no adverse move produces a call, and no gap can cost more than the debit.
You still need the permission tier. Interactive Brokers places long straddles and strangles at options permission Level 2 alongside debit spreads; short spreads and short puts are Level 3, and uncovered writing is Level 4. That scheme runs at every IBKR entity except the Indian and Canadian ones, so it governs a UK account — but the permission itself is still granted on an appropriateness assessment, not bought. Access is the UK obstacle: Hargreaves Lansdown, AJ Bell and Trading 212 offer no listed options in any account, so this is an IBKR or Saxo trade, and tastytrade is a US entity with SIPC cover rather than FSCS. Treat the ICE spread as a margin-equivalent cost — on the BP version a £13.45 round-trip bid-ask against a £134.51 debit starts the position 10% down. And note the trapdoor: finance the strangle by selling a strike against a leg and you have built a backspread, which is margin territory. Check the permission before you plan that adjustment, not during it.
both breakevens ≤ 1 standard deviation AND debit ≤ 40% of the at-the-money straddle. If a strangle only passes the 2%-of-account test once the strikes are past 1 SD, the position is too big — trade a smaller underlying, not a worse structure.Portfolio fit
This position contributes almost no net delta (+£0.31 a point), strongly positive vega (+£199.33 a volatility point) and negative theta (−£30.90 a day). It is the natural counterweight to a book of iron condors and credit spreads, which are short vega and long theta: one strangle offsets the vega of several condors and pays for the privilege in decay.
The binding constraint is size, and on a UK index it is brutal. At £1,310.46 a contract, one FTSE 100 strangle is 13.10% of a £10,000 account and 5.24% of a £25,000 one, and clearing the tier's 2%-per-position rule needs £65,523 of capital, because one contract is the minimum size and there is no smaller unit. That is the honest verdict: at the £10,000–£25,000 the Level 2 gate assumes, the index long strangle cannot be sized correctly, and the ICE single-stock version at £138.51 all-in (0.55% of £25,000) is the only route — bought with a 10% spread. Cap total long premium at 6% of the book, which on £25,000 is one FTSE contract or ten BP contracts, because a 5-point fall in implied volatility, from 14% to 9%, reprices a single index strangle £880.97 lower — 3.52% of that account — while standing still costs £216.31 a week.
What to trade instead
Simpler, from the tier below: a single long call or long put if you actually have a direction. Half the premium, half the decay, and no second leg quietly expiring worthless — the strangle's cost is that you pay twice to avoid choosing.
The nearer cousin: the long straddle. Both strikes at the money, £3,513.61 instead of £1,306.46, breakevens at 0.794 SD instead of 0.973, and a modelled 42.7% chance of finishing beyond one against 33.0%. Per £1,000 at risk the strangle buys 25.2 percentage points of win probability and the straddle 12.1 — the strangle is the better rate, the straddle the better trade if you can afford it.
More precise, from the tier above: the backspread is this same long-gamma idea, financed. Selling a nearer option to fund two further ones turns a £1,306.46 debit into a £193.56 credit, so a flat market pays instead of costing — in exchange for a £2,306.44 loss valley at the long strike, an upper breakeven 7.01% away, and exposure to one direction only. Take it when IV rank is too high to buy premium outright and you are willing to pick a side.
Risk statement
Listed options are complex instruments and most long-premium positions expire worthless; the modelled probability of this one finishing beyond a breakeven is 33.0%. This is educational material about mechanics and UK tax treatment, not a recommendation to trade the FTSE 100, BP or anything else, and it takes no account of your circumstances. Every premium here is modelled rather than quoted. If your trading becomes frequent enough to raise the investor-versus-trader question, that is one for a qualified adviser.