Stream Option Theta

Streams the real-time theta Greek for options contracts. Theta measures the rate of time decay - how much value an option loses each day, all else being equal.

Symbol Format

Options use OCC (Options Clearing Corporation) format:

  • Format: SYMBOL + YYMMDD + C/P + Strike(8 digits)
  • Example: AAPL240315C00170000 = AAPL Call, Mar 15 2024, Strike $170

Theta Characteristics

Scenario Theta Behavior
At-the-money Highest theta
Near expiration Theta accelerates
Long-dated Lower theta
Deep ITM/OTM Lower theta

Notes

  • Data streams automatically update in Excel
  • Theta is typically negative (options lose value over time)
  • Represents daily decay (weekends count too)

Examples

=QM_Stream_Theta("AAPL240315C00170000")
Theta for AAPL call
=QM_Stream_Theta("MSFT240315P00400000")
Theta for MSFT put
=QM_Stream_Theta(A1)
Option symbol from cell
=QM_Stream_Theta("AAPL240315C00170000")*7
Weekly time decay

When to Use

  • Time decay analysis
  • Option selling strategies
  • Position sizing for theta harvest
  • Understanding holding costs

When NOT to Use

Scenario Use Instead
Need delta QM_Stream_Delta()
Need gamma QM_Stream_Gamma()
Need vega QM_Stream_Vega()
Need implied volatility QM_Stream_ImpliedVolatality()

Common Issues & FAQ

Q: Why is theta negative? A: Options are wasting assets - they lose value as time passes. Negative theta reflects this decay.

Q: When does theta decay fastest? A: Theta accelerates as expiration approaches, especially for at-the-money options in the final weeks.

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