A long synthetic future buys an ATM call and sells an ATM put at the same strike and expiration. Net cost approximately zero (the call premium ≈ put premium at the ATM strike). The position behaves identically to long stock — same delta, same P&L curve.
Why traders use it: capital efficiency. A synthetic long requires only the margin for the short put, far less than buying 100 shares outright. The synthetic position has the same exposure as stock but doesn't tie up the full purchase price. Useful for capital-constrained accounts that want stock-like exposure without the capital outlay.
Risk warnings: the short put has assignment risk, and the position has unlimited downside (same as stock plus margin requirement). Margin calls can be triggered if the stock moves against you. Synthetic futures are not a beginner structure — they're a tool for traders who already understand stock margin mechanics and want options-based capital efficiency.
Frequently Asked Questions
Synthetic future or just buy the stock?
Synthetic is more capital-efficient but has assignment and margin call risk. Buy the stock if simplicity matters more than capital efficiency.
What's the put-call parity formula behind this?
Long stock = long call + short put at the same strike. The synthetic relationship holds because of arbitrage — any meaningful divergence would be traded away by market makers.