Synthetic Call¶
A synthetic call replicates the payoff of a long call option by combining a long stock position with a long put option at the same strike price and expiration date. The combination produces identical profit and loss outcomes to a long call, minus the cost of the put premium. The strategy is a direct application of put-call parity: long stock + long put = long call + cash.
HOW IT WORKS¶
The construction is straightforward: buy shares of the underlying and buy a put at the same strike and expiration you would have chosen for the call.
Payoff at expiration:
- Stock above strike — the put expires worthless; profit is the stock gain minus the put premium paid.
- Stock below strike — the put is exercised; the trader sells stock at the strike price and loses only the put premium.
Key levels:
| Metric | Formula |
|---|---|
| Total cost | Stock price + put premium |
| Breakeven | Stock purchase price + put premium |
| Maximum loss | Put premium paid |
| Maximum gain | Unlimited |
Example: NVDA trades at $180.00. A trader buys 100 shares at $180.00 and buys one $180 put at $4.50. Total cost: $18,450. If NVDA closes at $200 at expiration, the put expires worthless and profit is $1,550. If NVDA closes at $170, the put is exercised, stock is sold at $180, and the loss is limited to the $450 premium. Breakeven is $184.50.
Traders use synthetic calls when a put is underpriced relative to an equivalent call, when they prefer the tax or liquidity profile of stock, or when they want to cap further downside on an existing losing stock position without closing it.
Limitations: The strategy requires significantly more capital than a long call because the full stock position must be funded. The stock and put components have separate tax treatment. The put premium is still at risk if the stock stays above the strike through expiration. Deep in-the-money puts also carry early assignment risk near expiration.
IN TAPEBOARD¶
In the Tapeboard terminal, use the position builder to model a synthetic call before entry. Add a long stock leg and a long put leg at the same strike and expiration, and the payoff diagram will overlay the equivalent long call for direct comparison. The Greeks panel shows the combined delta, which starts near 1.0 and decreases as the put gains value on a move lower. Use the cost basis field to confirm your breakeven before placing the trade.