Stock prices fluctuate frequently. And if you’ve traded in the stock market for a significant period, you may be adept at identifying triggers like financial result announcements, budget notifications, MPC meetings, global events and companyspecific triggers. While these factors are common drivers of stock volatility, the options market is a whole different ball game.
In addition to the factors that also trigger stock price fluctuations, there is one other aspect that greatly impacts the price of options — the time left to expiration. This gives rise to the concept of time decay, which is easily quantified by the options Greek theta.
When you are choosing options trading strategies, you need to look beyond macro factors like the options putcall ratio (PCR) and implied volatility to assess how the theta impacts your strategy selection. In this article, we’ll take you through the meaning of time decay in options, how it’s measured using theta and delve into how you can master and apply the time decay of options to improve your trading success.
Decoding Time Decay in Options Contracts
Time decay in options is precisely what it sounds like. It means that as time passes and the options expiration nears, the option’s value decays or decreases. To understand this better, you need to first have greater clarity about the value of an options contract — which includes both intrinsic and extrinsic components.

Intrinsic Value
The intrinsic value of an options contract is essentially the profit it can generate if you exercise the right immediately. For example, say a call option has a strike price of ₹100, but the underlying asset is trading at ₹150. So, if you execute the options contract now, you can earn a profit of ₹50. This is the option’s intrinsic value. As the underlying asset’s price fluctuates, so does the option’s intrinsic value.

Extrinsic Value
The extrinsic value of an option depends on factors that are more abstract than its profit potential. The major factor that affects an option’s extrinsic value is the time left to expiration. The more time there is, the more the extrinsic value of the option will be. This is because you have a longer period over which you can potentially profit from the options contract.
However, as the expiry approaches, the extrinsic value of an option reduces. The rate at which this value decreases also accelerates as the expiry looms closer. This is primarily because as time passes, the probability of making profits by purchasing the option drastically reduces.
Measuring Time Decay in Options with Theta
Theta is the Greek term that quantifies the rate of time decay in options. It measures how much an option’s price decreases each day as it moves closer to expiry. It’s a critical metric for options traders because it reflects the rate at which time eats into the option’s value. Understanding theta can help you make informed decisions about entering the options market. It is also vital if you need to choose between holding an option versus selling it to capture its remaining value.
A high theta means the option is losing value quickly as expiry approaches. This makes any options trading strategy that requires you to hold long positions riskier as time runs out. For example, if an option has a theta of 0.20, it means the option’s price is expected to drop by ₹0.20 daily, if all other factors are equal. This metric becomes increasingly important as the expiry nears because the theta will grow higher, indicating an accelerated loss in the option’s value.
Mastering Time Decay can Help You Choose Winning Options Trading Strategies
At Samco Securities, we’ve integrated all the options Greeks including theta in the Samco trading app, so you can track the time decay of options even as the markets continue to change during each trading session.
Want to know why this matters?
To begin with, mastering time decay is crucial for choosing winning options trading strategies. Theta or the rate of time decay is inherent in all options. It affects their pricing and, consequently, impacts the options trading strategies that you can use to generate profits or hedge your risk.
Additionally, when you understand time decay, you can leverage it to select options trading strategies that align with your market outlook, risk tolerance and investment goals. With the Samco trading app, this becomes infinitely easier because our trading platform not only offers you a wealth of information about options Greeks — it also comes with an inbuilt options strategy builder that makes options trading strategy selection a breeze.
The Practical Significance of Time Decays in the Options Market
To accurately apply your knowledge of time decay in today’s markets, you need to understand that the impact of time on an option’s value is not linear. As we’ve seen earlier, it accelerates as the option approaches expiry. This is a critical aspect to keep in mind because it influences the selection of options trading strategies.
For example, if you are writing an option, you can benefit from time decay because the security you sell will lose value over time. This potentially allows you to buy back the option at a lower price or let them expire worthless. Plus, you get to keep the premium received from selling the option.
On the other hand, if you are an options buyer, you need to be aware that time decay works against you. The closer the option gets to its expiration date without moving ‘inthemoney’ (ITM), the less valuable it becomes. So, before you execute your options trading strategy, you need to have a strong conviction about the timing and direction of the underlying asset’s price movement to overcome the adverse effects of time decay.
To harness the power of time decay to your advantage, you can rely on relevant options trading strategies that account for an option’s decreasing value. For instance, the covered call options trading strategy involves holding a long position in an underlying asset and selling a call option on that same asset. The premium you receive from selling the call option provides some income, which can help offset the time decay if the market remains flat or slightly up.
Another strategy that accounts for the time decay is the iron condor, which involves selling both a call and a put option at different strike prices — but with the same expiration date. Simultaneously, you buy a call and a put option to limit risk. This strategy benefits from time decay if the underlying asset remains within a specific price range.
Keep Up with the Theta and Other Options Greeks on the Samco Trading App
With the Samco trading app, you can keep up with the theta and other options Greeks without having to switch between multiple platforms. That’s not all. At Samco, we believe in democratising trading for traders from all walks of life. So, the insights about options Greeks, time decay and even the best options trading strategies for any given market outlook are all available free of cost. Samco Securities does not levy any fee other than the standard Samco brokerage charges.
To gain the benefits of realtime market insights and other industryfirst features, all you need to do is switch to Samco today. The quick Samco account opening process means that you can start trading in the options segment and leverage your knowledge of time decay almost instantly.