Compare your current loan rate vs ZeroMargin
Enter your loan rate and a box spread rate to compare annual costs. ZeroMargin does not lend money or execute trades.
Model Inputs
Risk depends on the selected ZeroMargin rate.
As the ZeroMargin rate increases, risk gradually rises. At the top of the range, with a 7% annual yield, risk corresponds to an approximate 20% market drawdown: if the market falls beyond that level, the position moves into a loss zone.
- Enter the desired loan amount. We recommend keeping it below 30% of your Net Liquidation Value (NLV).
- Choose a horizon that matches your plan.
- Enter your loan rate and a box spread rate to compare annual costs. ZeroMargin does not lend money or execute trades.
- The box spread rate defaults to the latest ZMR; you can change it.
- Review outputs and risk, then reset if needed.
Modeled Outputs
RISK PANEL
Risk is shown as a required SPX drawdown threshold for losses to start under the selected ZeroMargin rate.
Assumptions & Disclosures
- Rates displayed are indicative and derived from public market data. Actual execution rates are market-dependent.
- Execution quality, timing, and bid-ask spreads will affect final financing costs. Modeled slippage is an estimate only.
- This calculator does not constitute investment, legal, or tax advice. Consult qualified professionals before acting.
- Box spread financing requires an options-eligible account with sufficient buying power and a supporting clearing arrangement.
- Historical spreads are not indicative of future rate differentials.
Analyst Note
This calculator is most useful when comparing existing broker margin costs against indicative box spread financing for positions you intend to hold for 6+ months. For shorter durations, execution costs may narrow the effective savings. Run multiple scenarios across the horizon toggle to model cumulative impact.
Risk Note
Modeled output can diverge from actual execution due to market volatility, liquidity conditions, and order routing. The calculator assumes mid-market fill; during periods of elevated VIX or low open interest, effective rates may widen. Always validate indicative rates against live markets before committing capital.
Research
Structured analysis of tax treatment, regulatory considerations, and governance frameworks relevant to synthetic borrowing via SPX box spreads.
Broker Margin vs. SBLOC vs. Box Spread
Comparative rate analysis, margin-call profile, and execution assumptions across financing vehicles.
Section 1256 and Box Spreads
Practical tax treatment framework for SPX-based synthetic financing and 60/40 implications.
Broker Margin vs. SBLOC vs. Box Spread
Comparative rate analysis, margin-call profile, and execution assumptions across financing vehicles.
Frequently Asked Questions
Common questions about the calculator methodology and output interpretation.
Are these rates real-time?
No. ZMR is calculated weekly from the midpoint between bid and ask at the close of a trading day. Broker and market rates come from published sources, and each shows its source and date. These are not executable quotes — check with your broker before acting.
Is the savings number guaranteed?
No. All outputs are modeled estimates based on the assumptions you input. Actual savings depend on execution quality, market conditions at the time of trade, slippage, and fees. The calculator is a planning tool, not a commitment.
Does this include fees and slippage?
By default, the basic calculation uses clean APR comparison. Toggle 'Advanced Assumptions' to add execution slippage (in bps) and an annual fees estimate. These adjustments reduce the modeled savings to provide a more conservative estimate.
Is this suitable for all account types?
Box spread financing requires a margin- and options-eligible brokerage account with sufficient buying power. Not all brokerages or account structures support this strategy. Consult your broker and compliance team before proceeding.
Can I model shorter tenors (e.g., 3 or 6 months)?
The current calculator supports Annual, 3-Year, and 5-Year horizons. For sub-annual modeling, divide the annual output accordingly. Note that shorter tenors may have different implied rates and proportionally higher execution cost impact.
How do I apply this to my account?
Check your broker's collateral requirements, options trading approval, and commissions. ZeroMargin does not analyze individual accounts and does not accept requests.