Open Interest vs Volume for Stock Options
What if there is only one trading day and the volume is smaller than   the open interest on that one trading day. This is assuming there is   no open interest before that day? I pulled this from a comment. This can't happen. We have zero open interest on day one. On day 2, I buy 10 contracts. Volume is 10 and now open interest is also 10. Tomorrow, if I don't sell, open interest starts at 10 and will rise by whatever new contracts are traded.   This is an example. I removed the stock name. This happens to be the Jan'17 expiration. The 10 contract traded on the $3 strike happen to be mine. You can see how open interest is cumulative, representing all outstanding contracts. It's obvious to me the shares traded as high as $5 at some point which created the interest (i.e. the desire) to trade this strike. Most activity tends to occur near the current price. You are asking 'what if', do you have some anticipated answers? Having volume smaller than open interest is the norm. As far as I can tell, having only one trading day and no previous open interest only affects someone trying to sell a contract they are holding.  Meaning that if you only have one day to sell your contract then you need to offer it 'at market' or at the bid price (or even lower than the bid price). If you cannot sell your contract then you have to let it expire worthless or you have to exercise it. Those are your three options: let it expire, sell it (perhaps at a loss), and exercise it.  Edit: be careful about holding an in-the-money option. Many brokers will automatically exercise an in-the-money contract if you hold it till expiration date. "For stock options, where I'm used to seeing these terms: Volume is usually reported per day, whereas open interest is cumulative. In addition, some volume closes positions and some opens positions.  For example, if I am long one contract and sell it to someone who was short one contract, then that adds to volume and reduces open interest.  If I hold no contracts and sell (creating a short position) to someone who also had no contracts, then I add to volume and I increase open interest. EDIT: With the clarification in your comment, then I would say some people opened and closed positions in that one day.  Their opening and closing trades both contribute to ""volume"" but they have not net position in the ""open interest."""
"Just as a matter of research, apparently there is a way to find high option volumes such as a site here: https://www.barchart.com/options/volume-leaders/stocks However, that information is going to be heavily skewed by ""underlying security that moved a lot more than expected and probably got a lot of positions filled incidentally today"", but I think it is a good place to start building up a list of securities with a lot of option interest. There is also a tab there for ETFs. This will not tell you exactly that a particular stock always has high option volume, but most of the ones that show up there repeatedly and across multiple strike prices will meet your criteria." The penny pilot program has a dramatic effect on increasing options liquidity. Bids can be posted at .01 penny increments instead of .05 increments. A lot of money is lost dealing with .05 increments. Issues are added to the penny pilot program based on existing liquidity in both the stock and the options market, but the utility of the penny pilot program outweighs the discretionary liquidity judgement that the CBOE makes to list issues in that program. The reason the CBOE doesn't list all stocks in the penny pilot program is because they believe that their data vendors cannot handle all of the market data. But they have been saying this since 2006 and storage and bandwidth technology has greatly improved since then. "Q: A: Everyone that is short is paying interest to the owners of the shares that the short seller borrowed. Although this quells your conundrum, this is also unrelated to the term. Interest in this context is just the number. In the options market, each contract also has an open interest, which tells you how many of that contract is being held. For your sake, think of it as ""how many are interested"", but really its just a completely different context." "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." I'm not exactly sure, but it may be due to liquidity preference.  SPY has a much higher volume (30d average of roughly 70m vs. 3.3m, 1.9m for IVV, VOO respectively), and similarly has a narrow bid ask spread of about 0.01 compared to 0.02 for the other two.  I could be wrong, but I'm going to leave this post up and look in to it later, I'm curious too. The difference is very consistent though, so it may be something in their methodology. Well, premium is the least of my worries. I would rather worry about that than have to worry about a margin call. I hate debt, and so this is the draw for me. I will check on that. I have a few books on options and derivatives, and I find it quite fascinating! I would really like a specific book on future options, but I will take a look through the books I have. Thanks! This is great, thank you. Can you think of any cases where expected return is greater than interest payments (like in #2) but the best choice would still be raise money through equity issuing? My intuition tells me this may be possible for an expensive company. Think of it this way:  1) You buy 1k in call options that will let you buy 100k of stock when they expire in the money in a year.   2) You take the 99k you would have spent on the stock and invest it in a risk free savings account.  3) Assume the person who sold you the call, immediately hedges the position by buying 100k of stock to deliver when the options expire.  The amount of money you could make on risk free interest needs to be comparable to the premium you paid the option writer for tying up their capital, or they wouldn't have made the trade. So higher risk free rates would mean a higher call price.   NOTE: The numbers are not equal because of the risk in writing the option, but they will move the same direction. "First, you mentioned your brother-in-law has ""$100,000 in stock options (fully vested)"". Do you mean his exercise cost would be $100,000, i.e. what he'd need to pay to buy the shares? If so, then what might be the estimated value of the shares acquired? Options having vested doesn't necessarily mean they possess value, merely that they may be exercised. Or did you mean the estimated intrinsic value of those options (estimated value less exercise cost) is $100,000? Speaking from my own experience, I'd like to address just the first part of your question: Have you treated this as you would a serious investment in any other company? That is, have you or your brother-in-law reviewed the company's financial statements for the last few years? Other than hearing from people with a vested interest (quite literally!) to pump up the stock with talk around the office, how do you know the company is: BTW, as an option holder only, your brother-in-law's rights to financial information may be limited. Will the company share these details anyway? Or, if he exercised at least one option to become a bona-fide shareholder, I believe he'd have rights to request the financial statements – but company bylaws vary, and different jurisdictions say different things about what can be restricted. Beyond the financial statements, here are some more things to consider: The worst-case risk you'd need to accept is zero liquidity and complete loss: If there's no eventual buy-out or IPO, the shares may (effectively) be worthless. Even if there is a private market, willing buyers may quickly dry up if company fortunes decline. Contrast this to public stock markets, where there's usually an opportunity to witness deterioration, exit at a loss, and preserve some capital. Of course, with great risk may come great reward. Do your own due diligence and convince yourself through a rigorous analysis — not hopes & dreams — that the investment might be worth the risk." Yes, from the point-of-view to the end speculator/investor in stocks, it is ludicrous to take on liabilities when you don't have to.  That's why single-stock options are far more liquid than single-stock futures. However, if you are a farmer with a huge mortgage depending upon the chaos of agricultural markets which are extremely volatile, a different structure might appeal to you.  You could long your inputs while shorting your outputs, locking in a profit.  That profit is probably lower than what one could expect over the long run without hedging, but it will surely be less volatile. Here's where the advantage of futures come in for that kind of structure: the margin on the longs and shorts can offset each other, forcing the farmer to have to put up much less of one's own money to hedge.  With options, this is not the case. Also, the gross margin between the inputs rarely fluctuate to an unmanageable degree, so if your shorts rise faster than your longs, you'll only have to post margin in the amount of the change in the net of the longs and shorts. This is why while options on commodities exist to satisfy speculators, futures are the most liquid. "Volume is really only valuable when compared to some other volume, either from a historical value, or from some other stock.  The article you linked to doesn't provide specific numbers for you to evaluate whether volume is high or low. Many people simply look at the charts and use a gut feel for whether a day's volume is ""high"" or ""low"" in their estimation. Typically, if a day's volume is not significantly taller than the usual volume, you wouldn't call it high. The same goes for low volume. If you want a more quantitative approach, a simple approach would be to use the normal distribution statistics: Calculate the mean volume and the standard deviation. Anything outside of 1.5 to 2.0 standard deviations (either high or low) could be significant in your analysis. You'll need to pick your own numbers (1.5 or 2.0 are just numbers I pulled out of thin air.) It's hard to read anything specific into volume, since for every seller, there's a buyer, and each has their reasons for doing so. The article you link to has some good examples of using volume as a basis for strengthening conclusions drawn using other factors." Since near-term at-the-money (ATM) options are generally the most liquid, the listed implied vol for a stock is usually pretty close to the nearest ATM volatility, but there's not a set convention that I'm aware of.  Also note that for most stocks, vol skew (the difference in vol between away-from-the-money and at-the-money options) is relatively small,  correct me if I'm wrong, IV is the markets assessment that the stock is about 70% likely (1 Standard Deviation) to move (in either direction) by that percent over the next year. Not exactly.  It's an annualized standard deviation of the anticipated movements over the time period of the option that it's implied from.  Implied vol for near-term options can be higher or lower than longer-term options, depending on if the market believes that there will be more uncertainty in the short-term.  Also, it's the bounds of the expected movement in that time period. so if a stock is at $100 with an implied vol of 30% for 1-year term options, then the market thinks that the stock will be somewhere between $70 and $130 after 1 year.  If you look at the implied vol for a 6-month term option, half of that vol is the range of expected movement in 6 months. It is a fool's errand to attribute abnormal option volume or volatility to any meaningful move in the stock. One side of the chain is frequently more expensive than the other. The relationship between historical volatility and implied volatility is dubious at best, and also a big area of study. "I'm adding to @Dilip's basic answer, to cover the additional points in your question.  I'll assume you are referring to publicly traded stock options, such as those found on the CBOE, and not an option contract entered into privately between two specific counterparties (e.g. as in an employer stock option plan). Since you are not obligated to exercise a call option you purchased on the market, you don't need to maintain funds on account for possible exercising.  You could instead let the option expire, or resell the option, neither of which requires funds available for purchase of the underlying shares. However, should you actually choose to exercise the call option (and usually this is done close to expiration, if at all), you will be required to fund your account much like if you bought the underlying shares in the first place.  Call your broker to determine the exact rules and timing for when they need the money for a call-option exercise. And to expand on the idea of ""cancelling"" an option you purchased: No, you cannot ""cancel"" an option contract, per se.  But, you are permitted to sell the call option to somebody else willing to buy, via the market.  When you sell your call option, you'll either make or lose money on the sale – depending on the price of the underlying shares at the time (are they in- or out- of the money?), volatility in the market, and remaining time value.  Once you sell, you're back to ""no position"".  That's not the same as ""cancelled"", but you are out of the trade, whether at profit or loss. Furthermore, the option writer (i.e. the seller who ""sold to open"" a position, in writing the call in the first place) is also not permitted to cancel the option he wrote.  However, the option writer is permitted to close out the original short position by simply buying back a matching call option on the market.  Again, this would occur at either profit or loss based on market prices at the time.  This second kind of buy order – i.e. made by someone who initially wrote a call option – is called a ""buy to close"", meaning the purchase of an offsetting position.  (The other kind of buy is the ""buy to open"".) Then, consider: Since an option buyer is free to re-sell the option purchased, and since an option writer (who ""sold to open"" the new contract) is also free to buy back an offsetting option, a process known as clearing is required to match remaining buyers exercising the call options held with the remaining option writers having open short positions for the contract.  For CBOE options, this clearing is performed by the Options Clearing Corporation.  Here's how it works (see here): What is the OCC? The Options Clearing Corporation is the sole issuer of all securities   options listed at the CBOE, four other U.S. stock exchanges and the   National Association of Securities Dealers, Inc. (NASD), and is the   entity through which all CBOE option transactions are ultimately   cleared. As the issuer of all options, OCC essentially takes the   opposite side of every option traded. Because OCC basically becomes   the buyer for every seller and the seller for every buyer, it allows   options traders to buy and sell in a secondary market without having   to find the original opposite party.   [...]   [emphasis above is mine] When a call option writer must deliver shares to a call option buyer exercising a call, it's called assignment.  (I have been assigned before, and it isn't pleasant to see a position called away that otherwise would have been very profitable if the call weren't written in the first place!) Also, re: ""I know my counter party cannot sell his shares"" ... that's not strictly true.  You are thinking of a covered call.  But, an option writer doesn't necessarily need to own the underlying shares.  Look up Naked call (Wikipedia).  Naked calls aren't frequently undertaken because a naked call ""is one of the riskiest options strategies because it carries unlimited risk"".  The average individual trader isn't usually permitted by their broker to enter such an order, but there are market participants who can do such a trade. Finally, you can learn more about options at The Options Industry Council (OIC)." I don't think that the trading volume would impact a broker's ability to find shares to short.  You might think that a lot more people are trying to short a stock during regular trading hours than in the pre-market, and that's probably true.  But what's also true is that a lot more people are covering their shorts during regular trading hours than in the pre-market.  For stocks that have difficulty in finding shares to short, any time someone covers a short is an opportunity for you to enter a short. If you want to short a stock and your broker is rejecting your order because they can't find shares to short, then I would recommend that you continue placing that order throughout the day.  You might get lucky and submit one of those orders right after someone else has covered their short and before anyone else can enter a short.  I have had success doing this in the past.