Files
ai/gateway/knowledge/trading/strategies/options/long-box.md
Tim Olson 47471b7700 Expand model tag support: add GLM-5.1, simplify Anthropic IDs, scan tags anywhere in message
- Flink update_bars debouncing
- update_bars subscription idempotency bugfix
- Price decimal correction bugfix of previous commit
- Add GLM-5.1 model tag alongside renamed GLM-5
- Use short Anthropic model IDs (sonnet/haiku/opus) instead of full version strings
- Allow @tags anywhere in message content, not just at start
- Return hasOtherContent flag instead of trimmed rest string
- Only trigger greeting stream when tag has no other content
- Update workspace knowledge base references to platform/workspace and platform/shapes
- Hierarchical knowledge base catalog
- 151 Trading Strategies knowledge base articles
- Shapes knowledge base article
- MutateShapes tool instead of workspace patch
2026-04-28 15:05:15 -04:00

35 lines
1.7 KiB
Markdown

---
description: "An arbitrage/volatility strategy combining a long synthetic forward and a short synthetic forward (or bull call spread and bear put spread) at two strikes, locking in a fixed payoff of K1 - K2."
tags: [options, arbitrage, neutral, box]
---
# Long Box
**Section**: 2.52 | **Asset Class**: Options | **Type**: Arbitrage
## Overview
The long box strategy can be viewed as a combination of a long synthetic forward and a short synthetic forward, or as a combination of a bull call spread and a bear put spread. It consists of: a long ITM put at K1, a short OTM put at K2 (lower), a long ITM call at K2, and a short OTM call at K1. The trader's outlook is neutral. This is a capital gain strategy. We assume K1 >= K2 + D.
## Construction
- Buy 1 ITM put option at strike K1 (higher)
- Sell 1 OTM put option at strike K2 (lower, K2 < K1)
- Buy 1 ITM call option at strike K2 (same as short put strike)
- Sell 1 OTM call option at strike K1 (same as long put strike)
- All same expiry
Net debit: D (assumed K1 >= K2 + D)
## Payoff Profile
f_T = (K1 - S_T)+ - (K2 - S_T)+ + (S_T - K2)+ - (S_T - K1)+ - D
= K1 - K2 - D (constant, regardless of S_T)
- P_max = (K1 - K2) - D (fixed payoff at all stock prices)
## Key Conditions / Signals
- Used primarily as an arbitrage strategy when the market price of the box (D) is less than the theoretical value (K1 - K2)
- Also used as a tax strategy in some jurisdictions (see footnote 31 in the source)
- No directional risk: the payoff is fixed regardless of stock price at expiry
## Notes
The long box has a deterministic payoff of K1 - K2 - D at expiry. If D < K1 - K2 (mispricing), this is a risk-free profit. In practice, transaction costs and bid-ask spreads must be considered. Can also be used as a synthetic loan.