Definition
Theta-Positive vs Theta-Negative
A theta-positive position earns money as time passes, while a theta-negative position loses value with each passing day.
Option sellers are theta-positive — every day of decay adds to their profit if the underlying behaves — which is why strategies like iron condors and short strangles are built around collecting theta. Option buyers are theta-negative, paying that decay daily and needing a move to overcome it.
Indian traders classify their book by net theta to know whether time is friend or foe: a net theta-positive book on Nifty or Bank Nifty profits from a calm, range-bound market into weekly expiry, while a theta-negative book needs movement and volatility to pay off.
Related terms
- Iron CondorAn iron condor sells an out-of-the-money call spread and put spread to earn premium in a range-bound market with defined risk.
- Theta Decay (Time Decay)Theta decay is the daily loss in an option's value purely due to the passage of time, accelerating as expiry nears.
Plain-English explainer from The Dispatch Investors Encyclopedia. General information, not financial advice.