How is options implied volatility for a stock determined?
"There are a few different ""kinds"" of implied volatility. They are all based on the IVs obtained from the option pricing model you use. (1) Basically, given a few different values (current stock price, time until expiration, right of option, exercise style, strike of the option, interest rates, dividends, etc), you can obtain the IV for a given option price. If you look at the bid of an option, you can calculate the IV for that bid. If you look at the ask, there's a different IV for the ask. You can then look at the mid price, then you have a different IV, and so on and so on. And that's for each strike, in each expiration cycle! So you have a ton of different IVs. (2) In many option trading platforms, you'll see another kind of IV: the IV for each specific expiration cycle. That's calculated based on some of the IVs I mentioned on topic (1). Some kind of aggregation (more on this later). (3) Finally, people often talk about ""the IV of stock XYZ"". That's, again, an aggregation calculated from many of the IVs mentioned on topic (1). Now, your question seems to be: which IVs, from which options, from which months, with which weight, are part of the expiration cycle IV or for the IV of the stock itself? It really depends on the trading platform you are talking about. But very frequently, people will use a calculation similar to how the CBOE calculates the VIX. Basically, the VIX is just like the IV described on topic (3) above, but specifically for SPX, the S&P 500 index. The very detailed procedure and formulas to calculate the VIX (ie, IV of SPX) is described here: http://cfe.cboe.com/education/vixprimer/about.aspx If you apply the same (or a similar) methodology to other stocks, you'll get what you could call ""the IV of stock XYZ""."
What you have to remember is that Options are derivatives of another asset like stocks for example.  The price of the Option is derived from the price of the underlying. If the underlying is a stock for example, as the price of the stock moves up and down during the trading day, so will the Market Maker's fair value for the Option.  As Options are usually less liquid than the underlying stock, Market Makers are usually more active in 'Providing a Market' with Options. Thus if you place a limit order half way between the current Bid and Ask and the underlying stock price moves towards your limit order, the Market Maker will do their job and 'Provide a Market' at that price, thus executing your order. My level of analysis is not quite that advanced. Can you share what that would show and why that particular measure is the one to use?  I've run regression on prices between the two. VIX prices have no correlation to the s&amp;p500 prices. Shouldn't true volatility result in the prices (more people putting options on the VIX during the bad times and driving that price up) correlate to the selloff that occurs within the S&amp;P500 during recessions and other events that would cause significant or minor volatility? My r2 showed no significance within a measurement of regression within Excel.  But, *gasp* I could be wrong, but would love to learn more about better ways of measurement :) Typically the settlement price for a financial instrument (such as AAPL stock) underlying a derivative contract is determined from the average price of trading in that instrument during some short time window specified by the exchange offering the derivative.  (Read the fine print on your contract to learn the exact date and time of that settlement period.) Because it's in an exchange's best interest to appear as fair as possible, the exchange will in general pick a high-volume period of time -- such as the close of trading on the expiry date -- in which to determine the settlement price. Now, the expiry date/time may be different from the last time at which the option can be traded, which may be different from the underlying settlement time.  For example, most US equity options currently expire on the Saturday following the third Friday of the month, whereas they can last be traded at end-of-day on the third Friday of the month, and the settlement period may be at a slightly different time on the third Friday of the month.  (Again, read the contract to know for sure.)  Moreover, your broker may demand to know whether you plan to exercise the option at an even earlier date/time. So, to answer your question: After-hours trading can only affect the settlement price of an underlying instrument if the exchange in question decides that the settlement period should happen during after-hours trading.  But since no exchange that wants to stay in business would possibly do that, the answer is no. Contract expiry time, contract exercise time, final contract trading time, and underlying settlement time may all fall at different dates/times.  The important one for your question is settlement time. "Your scenario depicts 2 ""in the money"" options, not ""at the money"". The former is when the share price is higher than the option strike, the second is when share price is right at strike. I agree this is a highly unlikely scenario, because everyone pricing options knows what everyone else in that stock is doing. Much about an option has everything to do with the remaining time to expiration. Depending on how much more the buyer believes the stock will go up before hitting the expiration date, that could make a big difference in which option they would buy. I agree with the others that if you're seeing this as ""real world"" then there must be something going on behind the scenes that someone else knows and you don't. I would tread with caution in such a situation and do my homework before making any move.   The other big factor that makes your question harder to answer more concisely is that you didn't tell us what the expiration dates on the options are. This makes a difference in how you evaluate them. We could probably be much more helpful to you if you could give us that information." Options, both puts and calls, are typically written/sold at different strike prices. For example, even though the stock of XYZ is currently trading at $12.50, there could be put options for prices ranging from $0.50 to $30.00, just as an example. There are several factors that go into determining the strike prices at which people are willing to write options. The writer/seller of an option is the person on the other side of the trade that has the opposite opinion of you. If you are interested in purchasing a put on a stock to hedge your downside, that means the writer/seller of the put is betting that you are wrong and that the stock price will rise instead. This paper makes the rounds every so often and I HATE IT VERY MUCH.  No one has EVER EVER EVER estimated standard deviation by taking an average of abs deviations, because that would be stupid, further, realized vol is a very different beast than implied vol. AND FURTHER, the models are fitted to the data, rather than fighting the tape and fitting the data to the models.   Most people working with these instruments are trying to figure out the prices of unknown derivatives based on known derivatives - the models just help interpret findings and estimate what's necessary to hedge a position. Outside of software that can calculate the returns:  You could calculate your possible returns on that leap spread as you ordinarily would, then place the return results of that and the return results for the covered call position side by side for any given price level of the stock you calculate, and net them out. (Netting out the dollar amounts, not percentage returns.)  Not a great answer, but there ya go. Software like OptionVue is expensive "Following comments to your question here, you posted a separate question about why SPY, SPX, and the options contract don't move perfectly together.  That's here Why don't SPY, SPX, and the e-mini s&p 500 track perfectly with each other? I provided an answer to that question and will build on it to answer what I think you're asking on this question.  Specifically, I explained what it means that these are ""all based on the S&P.""  Each is a different entity, and different market forces keep them aligned.  I think talking about ""technicals"" on options contracts is going to be too confusing since they are really a very different beast based on forward pricing models, so, for this question, I'll focus on only SPY and SPX. As in my other answer, it's only through specific market forces (the creation / redemption mechanism that I described in my other answer), that they track at all.  There's nothing automatic about this and it has nothing to do with some issuer of SPY actually holding stock in the companies that comprise the SPX index. (That's not to say that the company does or doesn't hold, just that this doesn't drive the prices.)  What ever technical signals you're tracking, will reflect all of the market forces at play.  For SPX (the index), that means some aggregate behavior of the component companies, computed in a ""mathematically pure"" way.  For SPY (the ETF), that means (a) the behavior of SPX and (b) the behavior of the ETF as it trades on the market, and (c) the action of the authorized participants.  These are simply different things. Which one is ""right""?  That depends on what you want to do.  In theory you might be able to do some analysis of technical signals on SPY and SPX and, for example, use that to make money on the way that they fail to track each other.  If you figure out how to do that, though, don't post it here.  Send it to me directly. :)" I would make a change to the answer from olchauvin: If you buy a call, that's because you expect that the value of call options will go up. So if you still think that options prices will go up, then a sell-off in the stock may be a good point to buy more calls for cheaper. It would be your call at that point (no pun intended). Here is some theory which may help. An options trader in a bank would say that the value of a call option can go up for two reasons: The VIX index is a measure of the levels of implied volatility, so you could intuitively say that when you trade options you are taking a view on two components: the underlying stock, and the level of the VIX index. Importantly, as you get closer to the expiry date this second effect diminishes: big jumps up in the VIX will produce smaller increases in the value of the call option. Taking this point to its limit, at maturity the value of the call option is only dependent on the price of the underlying stock. An options trader would say that the vega of a call option decreases as it gets closer to expiry. A consequence of this is that if pure options traders are naturally less inclined to buy and hold to expiry (because otherwise they would really just be taking a view on the stock price rather than the stock price & the implied volatility surface). Trading options without thinking too much about implied volatities is of course a valid strategy -- maybe you just use them because you will automatically have a mechanism which limits losses on your positions. But I am just trying to give you an impression of the bigger picture. "Many companies (particularly tech companies like Atlassian) grant their employees ""share options"" as part of their compensation. A share option is the right to buy a share in the company at a ""strike price"" specified when the option is granted. Typically these ""vest"" after 1-4 years so long as the employee stays with the company. Once they do vest, the employee can exercise them by paying the strike price - typically they'd do that if the shares are now more valuable. The amount they pay to exercise the option goes to the company and will show up in the $2.3 million quoted in the question." "Your company actually will most likely use some sort of options pricing model, either a binomial tree or black-scholes to determine the value for their accounting and, subsequently, for their issuance and realization.  First, market value of equity will be determined. Given you're private (although ""pre-IPO could mean public tomorrow,""), this will likely revolve around a DCF and/or market approaches.  Equity value will then be compared to a cap table to create an equity waterfall, where the different classes of stock and the different options will be valued along tranches. Keep in mind there might be liquidation preferences that would make options essentially further out of the money.  As such, your formulae above do not quite work. However, as an employee, it might be difficult to determine the necessary inputs to determine value.  To estimate it, however, look for three key pieces of information:  1. Current equity value  2. Option strike price  3. Maturity for Options  If the strike is close to the current equity value, and the maturity is long enough, and you expect the company to grow, then it would look like the options have more value than not.   Equity value can be derived from enterprise value, or by directly determining it via a DCF or guideline multiples.   Reliable forecasts should come from looking at the industry, listening to what management is saying, and then your own information as an insider." I asked a friend and he gave me a good explanation, so I'm just gonna paste it here for others: There is a simple and a complex answer depending on how much you want to understand the pricing dynamic of options.  LEAPs don't react 1:1 with a stock move because the probability of your option being in the money at expiry is still very much up in the air so you basically don't get full credit for a move in the stock this far out from expiry. The more complex answer involves a discussion of option 'greeks'.  Delta, Gamma, Theta, Vega, and Rho are variables that affect the pricing of all options.  The key greek in this case is Delta because it describes mathematically the expected move of an option as a ratio vs changes in stock price.  For put options the ratio is -1 to 0 where -1 is direct correlation between stock price and option price and 0 is no correlation.  The Delta increases as an option gets deeper in the money and also as it gets closer to expiry and reflects the probability of the option expiring in the money.  For your option contract the current Delta is -0.5673  so -3.38 * -0.5673 = 1.9 which is close.  Also keep in mind that that strike price had a last trade at 12:03 when the stock was at 13.3 and the current ask price is 22.30 so the last price isn't a true reflection of the market value.   As for the other greeks, Gamma is a reflection of volatility in the sense that it affects the rate of change of Delta as price and time changes.  Theta is the value of the time component of the option and is expressed as the expected time decay per day.  The problem is that the time premium is really some arbitrary number that the market maker seems to be able to change at will without justification and it can fluctuate wildly over short periods of time and I think this may explain some of the discrepancy.   If you bought the options when AAPL was $118.68 a couple weeks ago (option price of $18.85) and now AAPL is at $112.34 and the Delta over that time averaged at -0.55 then your expected option price would be $22.34 (($118.68 - $112.34) * 0.55 + 18.85 = $22.34) so you lost around $0.24 in time premium or 'Theta burn' over the last 2 weeks assuming it opens trading around 22.1 on Monday. Your broker should have information about the option contract greeks somewhere.  For my platform I have to put the cursor over top of the option contract for it to show me the greeks.  If your broker doesn't have this then you can get it from nasdaq.com. This is another reason that I only invest in deep in the money LEAPs because the time premium is much much lower than near the money and also because delta is much higher so if I want to trade out of it early I don't feel like I'm getting ripped off not getting paid for a stock price move.  For example look at the Jan 17 175 put.  The Delta is -0.9 and the time premium is only $0-1 depending if you are looking at the bid or ask.  The only downside is expected returns are lower for deep in the money contracts and they are expensive to buy. An option, by definition, is a guess about the future value of the stock. If you guess too aggressively, you lose the purchase price of the option; if you guess too conservatively, you may not take the option or may not gain as much as you might have. You need to figure out what you expect to happen, and how confident you are about it, against the cost of taking the option -- and be reasonably confident that the change in the stock's value will be at least large enough to cover the cost of buying into the game. Opinion: Unless you're comfortable with expectation values and bell curves around them, it's significantly easier to lose money on options than to profit on them. And I'm not convinced that even statisticians can really do this well. I've always been told that the best use for options is hedging an investment you've already made; treating them as your primary bet is gambling, not investment. I sell a put for a strike price at the market. The stock rises $50 over the next couple months. I've gotten the premium, but lost the rest of the potential gain, yet had the downside risk the whole time.  There's no free lunch.  Edit - you can use a BS (Black-Scholes) calculator to create your own back testing. The calculator shows a 1% interest rate, 2% yield, and 15% volatility produce a put price almost identical to the pricing I see for S&P (the SPY ETF, specifically) $205 put. No answer here, including mine, gave any reference to a study. If one exists, it will almost certainly be on an index, not individual stocks. Note that Jack's answer referencing PUTX does exactly that. The SPY ETF and it put options. My suggestion here would, in theory, let you analyze this strategy for individual stock options as well.  For SPY - With SPY at 204.40, this is the Put you'd look at -  12 times the premium is $33.36 or 16% the current price. The next part of the exercise is to see how the monthly ups and downs impact this return. A drop to $201 wipes out that month's premium.  It happens that it now March 18th, and despite a bad start to the year, we are at break-even YTD. A peek back shows In Dec you picked up $2.87 premium, (1.4% the current price then) but in Jan, it closed for a loss of $12. Ouch. Now, if you started in January, you'd have picked up 2 month's premiums and today or Monday sell the 3rd. You'd have 2.8% profit so far, vs the S&P break even.  Last, for now, when selling a naked put, you have to put up margin money. Not sure how much, but I use percent of the value of underlying stock to calculate returns. That choice is debatable, it just keeps percents clean. Else you put up no money and have infinite return. "Investopedia explains how a stock split impacts the stock's options: Each option contract is typically in control of 100 shares of an underlying security at a predetermined strike price. To find the new coverage of the option, take the split ratio and multiply by the old coverage (normally 100 shares). To find the new strike price, take the old strike price and divide by the split ratio. Say, for example, you own a call for 100 shares of XYZ with a strike price of $75. Now, if XYZ had a stock split of 2 for 1, then the option would now be for 200 shares with a strike price of $37.50. If, on the other hand, the stock split was 3 for 2, then the option would be for 150 shares with a strike price of $50. So, yes, a 2 for 1 stock split would halve the option strike prices.  Also, in case the Investopedia article isn't clear, after a split the options still control 100 shares per contract. Regarding how a dividend affects option prices, I found an article with a good explanation: As mentioned above, dividends payment could reduce the price of a stock due to reduction of the company's assets. It becomes intuitive to know that if a stock is expected to go down, its call options will drop in extrinsic value while its put options will gain in extrinsic value before it happens. Indeed, dividends deflate the extrinsic value of call options and inflate the extrinsic value of put options weeks or even months before an expected dividend payment.  Extrinsic value of Call Options are deflated due to dividends not only because of an expected reduction in the price of the stock but also due to the fact that call options buyers do not get paid the dividends that the stock buyers do. This makes call options of dividend paying stocks less attractive to own than the stocks itself, thereby depressing its extrinsic value. How much the value of call options drop due to dividends is really a function of its moneyness. In the money call options with high delta would be expected to drop the most on ex-date while out of the money call options with lower delta would be least affected. If a stock is expected to drop by a certain amount, that drop would already have been priced into the extrinsic value of its put options way beforehand. This is what happens to put options of dividend paying stocks. This effect is again a function of options moneyness but this time, in the money put options raise in extrinsic value more than out of the money put options. This is because in the money put options with delta of close to -1 would gain almost dollar or dollar on the drop of a stock. As such, in the money put options would rise in extrinsic value almost as much as the dividend rate itself while out of the money put options may not experience any changes since the dividend effect may not be strong enough to bring the stock down to take those out of the money put options in the money. So, no, a dividend of $1 will not necessarily decrease an option's price by $1 on the ex-dividend date.  It depends on whether it's a call or put option, and whether the option is ""in the money"" or ""out of the money"" and by how much."