The hedge calculator answers one question: How much hedging does this account need so that a crash does not trigger a forced liquidation, and what is the cheapest way to hedge? IBKR does not call you in a crash. As soon as excess liquidity turns negative, the broker liquidates in real time. The calculator therefore shows whether the account survives the path through a crash scenario and which measure closes a gap.
It always calculates exactly one account, because you buy the put in the account that holds the positions. Active, non-archived accounts at IBKR, Tastytrade and Schwab count as hedgeable. You can still select other accounts; they are just not preselected. Vault accounts cannot be read by sTraderZ.com and produce no calculation.
What counts as market risk
The measure is the beta-weighted delta exposure versus SPY (the S&P 500 ETF). An exposure of +€50,000 means: if the market falls 1%, you lose roughly €500 on paper.
| Instrument | Contribution to exposure |
|---|
| Stocks, ETFs, CFDs | Market value × β |
| Options | Black-Scholes delta × contracts × multiplier × underlying price × β (historical 30-day volatility, interest rate 4%) |
| Futures | Notional × β of the matching index ETF (ES/MES → SPY, NQ/MNQ → QQQ, RTY/M2K → IWM, YM/MYM → DIA), otherwise β of the future’s own market, otherwise 1.0 |
| Not included | Futures options, bonds, currencies and others. The page lists them individually. |
Path through the scenario and target buffer
A crash does not happen in a single step. The calculator splits the scenario into grid points with at most 5 percentage points of SPY move per step (7 steps for −34%). At each point, date, SPY price and VIX move linearly from today’s level to the final value. Each position moves by crash β × SPY move. Options are fully revalued with the remaining time to expiry as of the point’s date.
- Liquidation value (NAV) today: the broker snapshot if it is no older than 5 weekdays; otherwise cash plus market values (excluding the notional value of futures, futures options and CFDs). The page names the source.
- NAV at a grid point: NAV today plus the gain or loss of all positions (futures as cash) plus the value of the hedge.
- Buffer = NAV − estimated maintenance margin × crisis surcharge. The crisis surcharge rises linearly to +25% at the end of the scenario, because brokers raise their rates in volatile phases (cautious assumption).
- What matters is the smallest buffer along the whole path: the margin call comes on the way down, not only at the end.
- The target buffer (0 to 80% of today’s NAV, default 10%) is your safety margin. Prices gap overnight, and the estimate is imprecise.
Hedge at least is a linear reference value without costs and without its own margin: the smallest crash-β exposure whose hedge lifts the buffer to the target buffer at every point. At most useful is the entire crash-β exposure (β-neutral); more hedging would be a bet on falling prices. Both values are shown in euros and as SPY shares. If an actual IBKR margin value is available for the account, it appears below the estimate, with its date and the ratio actual/estimated.
📊 Reading the result: room until margin call
At the top there is one number: the room until margin call. It tells you how far the S&P 500 can fall before the buffer drops to zero and the broker starts liquidating. For this, sTraderZ.com calculates its own depth path in steps of 5 percentage points down to −60 %, plus the low point of your scenario as a point of its own. Between the two points where the buffer drops below zero, the calculator halves the gap three times and only then interpolates linearly, because the buffer curve is curved when options are involved. Since the figure rests on an estimate (prices via β, estimated margin, a flat crisis surcharge), it is rounded to whole percent and shown with “≈”, for example “≈ −22 %”; matrix and curve show one decimal. If the buffer holds all the way to −60 %, it reads “> −60 %”. At IBKR, zero buffer means forced liquidation with no grace period for a deposit: the broker closes positions automatically. A bar below splits the liquidation value into margin and buffer. Up to the depth of your scenario, time, VIX and crisis surcharge follow the scenario path; beyond it, time and VIX are extended with the same slope.
- 🟢 Green: the margin call lies deeper than your scenario, and the target buffer holds.
- 🟡 Yellow: no margin call within the scenario, but the target buffer breaks along the way (the sentence says from which depth).
- 🔴 Red: the margin call comes within your scenario or has already been reached today.
- If an existing hedge expires within the next 60 days, the sentence also gives the room after the expiry. Warnings and data sources are collapsed under “notes”.
Whatever you want to try out, you control in the ⚙️ What if … panel to the right of the result. At the top of the panel are three tabs: “🛡️ Existing” (existing hedges), “➕ Measures” (further protection) and “🔒 Positions” (closing positions on trial); the number on a tab counts your changes there. Clicking a matrix row shows the detail of that measure in place of the tab, and “Back” returns to the tab you last chose. On a phone the panel opens as a bottom sheet from below. The scenario (crash depth, VIX peak, duration and “Crash starts in … days”) is not set in the panel but in the large “Crash scenario” window. It opens from the scenario line at the top, with “✏️ Change scenario” or by clicking a scenario chip. Every change appears as a chip under the headline number; the ✕ on a chip undoes it, and “Reset everything” restores the account as it is today. Depending on screen width, result and panel sit in one or two columns. The four sections follow below:
| Section | What it shows |
|---|
| 🎛️ Crash simulator | Curve of the buffer by crash depth with the measures shown, with the protection timeline below |
| 📊 Buffer by crash depth | Decision list: one row per account situation or measure with buffer in scenario, gain, cost, value per € and room until the call; “Values per depth” shows the buffer at every crash depth |
| 🔍 Measure in detail | Order, price per leg, key figures and “Why this one first” for the clicked matrix row; this is also where you add your own hedges |
| 📋 Positions | Contribution of each position in the crash and “room without”; positions are closed on trial in the panel |
🎛️ Crash simulator
- Scenario: crash depth, VIX peak and duration to the low are set in the “Crash scenario” window, on the map or in the fields, with “Crash starts in” below the map; a change recalculates. The duration snaps to the five time horizons. The crash depth moves the vertical marker in the curve immediately.
- Crash starts in (0 to 120 days) moves the start of the crash into the future. Hedges that expire before then are missing, the time value of the options until the start is included, and the market moves sideways until then. The headline number and the curve show the room for that start.
- Curve: buffer in € over the crash depth. Grey is the account today, dashed grey the account without its existing hedges, indigo the measures shown (at most three at a time). The yellow area marks “below target”, the red one the margin call, the dashed line the target buffer. Every zero crossing carries a marker with its percentage. Beyond your scenario the curve is lighter because it is extended there. With the mouse (on a phone by tapping) a crosshair shows buffer, margin, NAV and day at every depth.
- Existing hedges: the calculator detects hedges in the account itself. To do so it joins options on the same underlying with the same quantity into pairs: spread, collar, or across different expiries diagonal or calendar. A pair counts as a hedge if it gains net in a crash; it expires with the earlier expiry. Remaining options with the same underlying and expiry form a group under the same rule. A bull put spread or a covered short call therefore does not count, whereas a put spread next to short puts of the same expiry does. An iron condor splits into two spreads, of which only the call side hedges. Each entry shows the days left (yellow below 30, red below 7 days), value today, gain in the crash, time decay per day and the room without it. In the panel under “🛡️ Existing hedges”, a switch takes it out on trial; the change then appears as a chip under the headline number.
⏳ Protection timeline
The bar below the curve covers the next 120 days. Each segment runs from the expiry of one hedge to the next and gives the room if the crash starts in that period: green if the margin call lies deeper than your scenario, yellow if the target buffer breaks within the scenario, red if the margin call lies within the scenario. Markers show the expiries, the low point of the scenario and the start set with the “Crash starts in” slider. Short options that expire in the money before then are assigned, and the segment names the assignment. Without any hedge in the account there is just one segment.
📊 Buffer by crash depth
- Cells: buffer in € at the given crash depth. Background green (buffer at least the target buffer), yellow (between 0 and the target), red (0 or less: margin call). Columns beyond the scenario are paler. Below each depth is the day on the path.
- Account group: the account today, one row “from DD.MM.YYYY” per hedge expiry (crash starts after the expiry) and, as soon as you close positions, a row “with … closed” with the buyback amount as cost.
- Measures group: each row is the starting situation plus one measure. Each row shows the buffer in the scenario, the gain (the difference to the starting situation, with a bar), the cost, the value per € (gain divided by cost; “Price missing” for estimated prices below €10) and the room. The list is sorted by gain; clicking a column header sorts by that column, a second click reverses the order. The label “cheapest” marks the financeable measure with the lowest cost per year that holds the target buffer. On the right is the room with the difference to the starting situation in percentage points.
- New in the catalogue: “roll” for every existing long put that expires soon (same strike, expiry at least 90 days away; buys time, not depth), and “Buy back short options”. That row is preset with the short option with the largest crash contribution; “Select positions” opens the panel on the “🔒 Positions” tab, filtered to short options, where you change the selection with the switches.
- Using it: clicking a row opens “Measure in detail”. The info symbol after the name explains the measure in a tooltip; you show a measure in the curve in the panel under “➕ More protection”. “Combine two measures” calculates two rows together and shows them as a row of their own, “a + b”. In a narrow card only measure, gain and value per € remain; “Values per depth” shows the buffer at every crash depth.
🔍 Measure in detail and your own price
The detail gives the order per leg, cost today and per year, gain in the crash, buffer at the low, whether the measure can be financed today, and its catches. On the right, “Why this one first” lists room per €1,000, gain per €1 of cost at −20 %, down to which depth the target buffer holds, margin relief today and a comparison with the next row. “Apply to simulator” shows the measure in the curve.
Overriding the price: premiums are estimates from VIX and skew. If you enter your broker’s price in the price field of a leg (0.01 to 10,000 per unit), sTraderZ.com recalculates the row, the costs and the curve with it, and the source reads “from you”. The price applies to this account for as long as the browser session runs.
➕ Your own hedge
Below the matrix you can add up to 5 hedges of your own per account. They appear as rows with a pencil (edit) and a bin (delete).
| Type | Underlying |
|---|
| Long put, put spread, collar | SPY or an underlying you hold in the account |
| Short future (MES/ES), short ETF | SPY only (both track the index, not the single stock) |
- Strike: absolute or in % out of the money. One row per leg (“put bought”, “put sold”, “call sold”). Prefilled are the bought put 5 % out of the money, in a spread the sold put 15 %, in a collar the call 5 % above the price. Spread and collar need two strikes: in a put spread the bought strike is above the sold one, in a collar the put is below and the call above the price.
- Expiry: preset to the first monthly expiry at least 30 days away, at most 3 years away.
- Quantity: leaving it empty means “smallest quantity that holds the target buffer”.
- Price per share: calculated while you type and shown as a grey value in the field, next to the volatility used (IV), with the net amount per contract below. Leave it empty and this estimate applies. Enter your broker's quote and the calculator uses that. SPY options are estimated from the VIX curve with a skew surcharge on bought puts, options on single stocks from the historical volatility of the underlying, without skew.
- Your own hedges only apply during the current browser session. They are not saved and not calculated by the monitoring.
📋 Positions and closing on trial
- Each rated position is shown with its contribution at the chosen depth (−5 %, −10 %, −20 % or scenario). Drivers lose (bar to the left, red), hedges gain (bar to the right, green). The contribution is the full revaluation of the position, so for options it is not linear. The eight largest drivers are listed one by one, the rest under “more”.
- Room without is the room until margin call if this position were closed. That way you see which closing helps most before you touch anything. If you have already closed positions on trial or moved the start of the crash, the column calculates from that starting point, like all other figures.
- In the panel under “🔒 Close positions on trial”, the close switch takes the position out of the account on trial. The headline number, the curve, the matrix (row “with … closed”) and all measures then start from this situation. A note below the row gives the buyback cost or proceeds, the change in margin today and the room before and after. Spread, commission and taxes are not included.
- Clicking the row shows β, crash β, R², σ, market value, margin increase and a sentence that explains the contribution.
The page remembers switches, measures shown, your own prices and your own hedges per account for as long as the browser session runs. Switching accounts starts fresh.
Margin estimate
The estimate follows the structure of IBKR’s margin but does not replicate it exactly.
| Component | Rule in the calculator |
|---|
| Portfolio margin: classes | One class per underlying. Options belong to their underlying, the SPY hedge to the SPY class. |
| Range for broad US indices | +6% / −8% (SPY, IVV, VOO, SPX, SPXW, XSP, QQQ, NDX, NDXP, DIA, VTI, RSP) |
| Range for small-cap indices | ±10% (IWM, RUT, RUTW) |
| Range for all other securities | ±15% on the class’s own price |
| Grid | 10 points across the range (including both ends), options at each point with σ × 0.75 and σ × 1.25. Class loss = largest loss of the 20 valuations, at least USD 0.375 × multiplier per option contract. |
| Index group | Broad indices are combined point by point. Gains in one class offset losses in others at 80% (OCC cites 90%, rounded down to be cautious). |
| Concentration | The two classes with the largest loss at ±30% (options with σ × 1.25) plus the rest at ±5% × β. Portfolio margin = the larger of class total and concentration. |
| Reg T: stocks and ETFs | long 25%, short 30% of market value; initial margin 50% (only for “affordable today”) |
| Reg T: options | Long 0. Uncovered short: premium + max(20% × price − OTM amount, 10% × price for a call or strike for a put); indices from the list above 15% instead of 20%. Short call against shares of the same class: 0. Vertical spread: maximum loss. |
| Futures segment | Notional × 6% (equity index futures ES, MES, NQ, MNQ, RTY, M2K, YM, MYM, FESX, FDAX, FDXM, FSXE) or 12% (others) × volatility factor VIX at the point ÷ VIX today (at least 1, at most 2.5). No offset against the securities segment. |
| Crisis surcharge | total margin × (1 + 0.25 × progress through the scenario) |
Important under portfolio margin: An SPY put only offsets within the index group. It barely lowers the margin on your single stocks. It helps almost only through its value in the crash, which supports the liquidation value.
Reg T, unconfirmed assumption: The calculator counts the value of purchased puts as equity. Whether IBKR counts purchased US options towards Equity with Loan Value under Reg T is not confirmed. If not, a put only protects you once you sell it. For Reg T accounts, plan with a larger cushion.
Crash β and R²
- β is calculated over 252 trading days against SPY, matched day by day by date. With fewer than 60 common trading days, β = 1.0 applies and the row is marked “assumed”.
- Downside β: the same regression, only over days on which SPY fell. With fewer than 30 such days, the normal β applies.
- Crash β = the larger of β and downside β. Correlations rise in a crash; the one-year β underestimates defensive stocks in particular. A negative β stays unchanged.
- R² is the coefficient of determination of the same regression. If it is below 0.3 (or unknown), the position can hardly be hedged via SPY. If such positions make up 20% of the exposure or more, the page shows a notice, and the verdict at the top adds that the figure is less certain for that reason.
- Volatility of existing positions: σ at the point = σ today + β × (VIX at the point − VIX today) ÷ 100, never lower. σ today is the historical 30-day volatility.
Volatility term structure of the hedge
The implied volatilities of the SPY options come from VIX (30 days), VIX3M (91 days) and VIX6M (182 days), linear by maturity in between. Today, purchased puts get a skew surcharge of 4 vol points per 10% out of the money (makes puts more expensive); sold options get none, neither the call in the collar nor the 15% put in the spread (brings in less). In a crash, the volatility of long maturities rises much less than the VIX. The damping comes from the Covid crash:
| Maturity | Index | before the crash (≈) | 16 Mar 2020 | Damping in the calculator |
|---|
| 30 days | VIX | 14 | 82.7 | 1.00 |
| 91 days | VIX3M | 16 | 57.7 | 0.61 |
| 182 days | VIX6M | 18 | 47.8 | 0.43 |
| over 182 days | – | – | – | 0.43 × √(182 ÷ days) |
IV in the crash = IV today + (VIX at the point − VIX today) × damping, without skew surcharge (cautious: lower gain). Valuation uses Black-Scholes-Merton, interest rate 4%, SPY dividend yield 1.3%. VIX today is the latest close. If it is older than 5 weekdays or missing, the calculator falls back to the historical 30-day volatility of SPY as a flat curve and says so. If only VIX3M or VIX6M is missing, the curve stays flat from the last available value.
Overriding VIX today: A custom value shifts the whole curve by the difference and the volatility of existing positions by β × difference ÷ 100 (at least 5%). It does not change today’s NAV. It only affects future volatility and thus the cost of the hedge and the path through the scenario.
Scenario templates
| Template | S&P 500 (SPY) | VIX in the crash | Time horizon |
|---|
| Black Monday 1987 | −20% | 150 | instant |
| Volatility shock Aug. 2024 | −8% | 65 | 1 month |
| Correction 2022 | −25% | 36 | 6 months |
| Covid 2020 (default) | −34% | 82 | 1 month |
| Financial crisis 2008 | −57% | 80 | 1 year |
| Custom | −80 to −1% | 5 to 200 | free |
VIX 1987 is the VXO close at the time (the VIX did not exist yet), VIX Aug. 2024 the intraday high, because margin is calculated in real time. Time horizons: instant, 1 month (30 days), 3 months (91), 6 months (182), 1 year (365). VIX today can be set from 5 to 100.
Measures compared
| Measure | Implementation in the calculator | Cost, cost per year | Catch |
|---|
| Reduce exposure | Shrink all positions (including options and futures) proportionally, amount in whole percent | 0.1% of the gross market value sold (futures: notional), one-off | Gains and taxes are realised (not calculated); upside potential shrinks as well |
| Put 5% OTM, ≈ 1 or 3 months | SPY put, strike rounded down to USD 1; expiry on the third Friday closest to 30 or 91 days, at least 21 days | Premium × 1.03; per year cost × 365 ÷ days to expiry | Must be rolled often; under portfolio margin it barely lowers the margin on single stocks |
| Put 10% OTM, ≈ 1 or 3 months | as above, 10% out of the money | as above | Only kicks in after a 10% drop |
| Put spread 5/15%, ≈ 3 months | Long put 5%, short put 15% out of the money | Long premium × 1.03 − short premium × 0.97 | Protection ends at −15% |
| Collar, ≈ 3 months | Long put 5% OTM, short call 5% OTM (strike rounded up) | Put premium × 1.03 − call premium × 0.97 | Upside capped; the short call requires margin |
| MES short | Micro E-mini S&P 500, notional per contract 5 × S&P level ≈ 50 × SPY price, linear gain | 0 (carry ignored); separate futures margin | No upside; from 10 MES, 1 ES would be equivalent |
| Short ETF (−1×) | SH or a UCITS short ETF on the S&P 500, amount in €1,000 blocks; gain −1 × SPY move without path dependency; margin like a long stock (PM ±15%, Reg T 25%) | Purchase price; per year 4% interest on the tied-up capital + 0.9% expense ratio | SH cannot be bought by EU retail clients because of PRIIPs (no key information document), a UCITS short ETF can; ties up capital; daily reset |
| Long-dated put (only for 6 months or 1 year) | SPY put 5% OTM, first December expiry from the end of the horizon, at most 2 years | as above | Under portfolio margin it barely lowers the margin on single stocks |
- Amount: the smallest whole number of units (reduce exposure: smallest whole percentage) at which the smallest buffer along the path reaches the target buffer. If a measure cannot achieve this within the β-neutral amount, it shows “not achievable”. The β-neutral toggle shows the full hedge: notional = crash-β exposure (puts: contracts × 100 × SPY price), reduce exposure = 100%.
- Gain in the crash: NAV with the measure at its own lowest buffer point minus NAV without the measure at the same index level. The value is net; costs are already deducted.
- Valuation in the crash: Purchased hedge options count with a 3% discount (sale price), sold ones (the call in the collar) with a 3% markup (buyback price).
- Affordable today: surplus = NAV − margin today (Reg T: initial margin). Cost plus margin increase must fit into it. Reducing exposure is always affordable. Rows that are not affordable remain visible, are marked and are never highlighted.
- The highlighted row is the affordable measure with the lowest cost per year that reaches the target buffer (reducing exposure counts with its one-off cost).
- Rolling: If a put expires before the end of the horizon, the row states how often it would have to be rolled. Rolling itself is not included; in a crash it is more expensive.
- VIX calls are a well-known alternative: they rise disproportionately in a crash. Their price, however, depends on VIX futures, not on the VIX itself, and that basis cannot be recalculated reliably. The calculator therefore does not list them as a row.
Portfolio margin: minimum equity
IBKR requires a net liquidation value of at least USD 100,000 for portfolio margin. Below that, only trades that reduce margin are allowed. If NAV falls below this threshold along the path (converted into euros at today’s rate), the page shows a warning. The calculation stays on portfolio margin; switching to Reg T would only increase the margin.
Currency
Calculations and display are in euros, converted at today’s rate, which stays constant throughout the scenario. In past crashes the US dollar mostly appreciated. For a euro account holding US stocks, the constant rate is therefore rather cautious; for a loan in US dollars it is not, because the debt then grows in euros. β is calculated from returns in the trading currency, so the exchange-rate move against the dollar is not included in it.
Limits of the calculation
| Limit | Meaning |
|---|
| Margin | An approximation of IBKR’s margin, not an exact replica. Compare with the actual value when it is shown. |
| Costs | Estimates using Black-Scholes-Merton with estimated implied volatility, no live premiums |
| Model | Single-factor model: everything moves with crash β × SPY. Single-stock risk, price gaps and correlation breaks are missing. |
| Expiry along the path | If an option expires during the path, the price on the expiry date is interpolated. Short options in the money are assigned and continue as a stock position, with margin. Long options in the money are closed at intrinsic value. Options out of the money expire worthless. |
| VIX today | A custom value does not change today’s NAV, only future volatility. |
| Reg T | Purchased puts count as equity; whether IBKR treats them the same way under Reg T is not confirmed. |
| Short ETF, MES | Short ETF without the path dependency of the daily reset; MES without carry |
| Not calculated | Rolling, taxes on reducing exposure, futures options |
Data checks: If the stored expiry of an option differs from the expiry in the OCC symbol, the value from the symbol is used. Expired options are excluded, duplicate position rows count once, and stale holdings and prices are flagged.
Monitoring: 📡 After the US market close, sTraderZ.com recalculates every day for each account using the settings you saved last, and stores the result as a history. You are notified only when the state changes: the buffer falls below your target, the gap grows by half and by at least €500, or the all-clear comes once the buffer is at least 5 % above the target. Delivery happens between 7 am and 9 pm, through the same channels as the action rules. You choose them right in the “Monitoring” block under “Notify via” (bell always, plus push, email or Telegram) or under Profile → Notifications. If only the bell is on, you only see a warning the next time you log in; the block points this out. With "Understood, stop notifying me" you mute a warning until the situation worsens significantly: escalations and all-clears still come through. Days that cannot be assessed (stale prices, missing cash) report nothing; after 5 such days a note appears in the bell. You can switch monitoring off per account with the switch in the “Monitoring” block: the account is then no longer calculated at night and sends no notifications, while its history stays visible.
You can find the calculator under Trading System → Hedge calculator (Premium).
Calculation aid, not investment advice.