Credit and debit spreads chart
Chart how a two-leg vertical spread has priced over time - net premium, each leg's premium, volume, open interest, implied volatility and Greeks - next to the stock price.
Overview
The Credit Debit Spreads chart follows one vertical spread - two options of the same type and expiration at different strikes, one sold and one bought - through every stored capture in a date range. It shows the spread's net premium, each leg's premium, volume, open interest, implied volatility and Greeks, and the stock price, so you can study how a specific spread has behaved rather than how it looks at a single moment.
To find spreads to look at, use the Credit / debit spreads report; this chart is where you look at one of them over time.
The data delay depends on your plan and is shown on every view; the stock price line above the charts is marked "(delayed)".
Before you start
- The chart is part of Research → Charts, shown on plans that include advanced analytics.
- Your plan's history allowance sets the earliest date; on the Free plan the latest capture is the previous session's close.
- Know the four spread types and which leg is sold:
| Spread type | Leg 1 (sell) | Leg 2 (buy) | Net premium |
|---|---|---|---|
| Bull Call Debit Spread (default) | Higher call | Lower call | Buy premium - sell premium (a debit) |
| Bear Put Debit Spread | Lower put | Higher put | Buy premium - sell premium (a debit) |
| Bear Call Credit Spread | Lower call | Higher call | Sell premium - buy premium (a credit) |
| Bull Put Credit Spread | Higher put | Lower put | Sell premium - buy premium (a credit) |
Steps
- Open Research → Charts and choose Credit Debit Spreads.
- Pick a symbol, then an Option Expiry. Past expirations are listed too, so you can review a spread after it expired.
- Choose the Spread Type. The leg lists switch between call and put strikes to match it.
- Choose the sell strike (Leg 1) and the buy strike (Leg 2) from the two strike lists.
- Adjust Start date and End date (default: the last 30 days) and press Generate.
- Drag the slider under any chart to zoom; Reset zoom shows every capture again.
Columns and metrics
| Chart | What it means |
|---|---|
| Option Premium Price Difference | Net premium of the spread per share at each capture: credit = sell - buy, debit = buy - sell. |
| Option Premium Price | Each leg's premium (mark, the mid of bid and ask) per share. |
| Volume | Session volume of each leg at each capture. |
| Stock Price | The underlying's price at each capture. |
| Open Interest | Open interest of each leg. |
| Implied Volatility | Each leg's implied volatility, shown as a percentage. |
| Delta, Gamma, Theta, Vega, Rho | Each leg's Greeks as supplied with the snapshot; blank when the provider did not publish them. |
Above the charts, a line shows the latest stock price in the range, its time in ET and the spread type name. Only captures where both legs were recorded at the same instant are plotted.
How to read it
- Net premium over time. For a debit spread, a rising line means the spread has become more expensive to buy; for a credit spread, a falling line means less credit is available. Read it next to Stock Price to see how the spread responded to the stock's moves.
- Leg premiums. Option Premium Price shows which leg drove a change in net premium.
- Liquidity. Low or zero Volume and Open Interest on a leg means its mark may rest on a wide bid-ask spread, so its premium is less reliable.
- Implied volatility per leg. A gap between the two legs' IV (the volatility skew between the strikes) affects the net premium even when the stock does not move.
- Greeks. The difference between the legs' Delta shows how sensitive the spread is to the stock price; Theta shows how each leg's value is expected to change as time passes.
Example
Illustrative data only. XYZ trades at 50. You chart a Bull Call Debit Spread on the nearest monthly expiration, selling the 55 call and buying the 50 call. Over 15 sessions Option Premium Price Difference rises from 2.00 to 3.00 while Stock Price moves from 50 to 53, and the 50 call's Delta rises from 0.50 to 0.65. The chart shows the spread's cost tracking the stock higher; it does not say whether that will continue.
Using it in your research
- How did a spread from the report behave before today? Take a row from the Credit / debit spreads report and chart its legs over the past month.
- How sensitive is the spread to the stock? Compare the net premium line with the stock price line across several sessions.
- Is time decay visible? On a quiet stretch where the stock is flat, watch how the net premium and each leg's Theta change.
- Is the spread liquid enough to study? Check both legs' volume and open interest before relying on their marks.
- For the definitions of premium, IV and the Greeks, see the Metric glossary.
Troubleshooting
"Please select Option Expiry Date" or a sell or buy strike message
Every input is required. Choose the expiration first; the strike lists fill in after it.
"Sell Strike Price (Leg 1) should be LESS than Buy Strike Price (Leg 2)" (or GREATER)
The strikes are the wrong way round for the spread type. Check the table under Before you start and swap the legs.
"No records found"
No capture had both legs recorded in the range. Widen the dates, or pick strikes nearer the stock price, where contracts are captured more consistently.