Options liquidity and trading positions larger than the daily volume?
You definitely cannot be guaranteed to get the bid or ask if you are selling more than are available/desired at those prices. What prices you do get depends on who is watching that contract and how willing they are to trade with you. This question is not much different from the question of whether you can easily get into or out of a large position in an illiquid small stock easily.  You can get out quickly if you are willing to take pennies on the dollar, or you may get a reasonable price if you take a long time to get out of (or into) your position.  You can't normally do both. In general taking large positions in illiquid assets is not something people want to do without lining up a buyer/seller beforehand.  Instead see if you can achieve your objective with liquid investments. One broker told me that I have to simply read the ask size and the bid size, seeing what the market makers are offering. This implies that my order would have to match that price exactly, which is unfortunate because options contract spreads can be WIDE. Also, if my planned position size is larger than the best bid/best ask, then I should break up the order, which is also unfortunate because most brokers charge a lot for options orders.
Yes, and there's a good reason they might. (I'm gonna use equity options for the example; FX options are my thing, but they typically trade European style). The catch is dividends.  Imagine you're long a deep-ITM call on a stock that's about to pay a dividend. If that dividend is larger than the time value remaining on the option, you'd prefer to exercise early - giving you the stock and the dividend payment - rather than hanging on to the time value of the option.  You can get a similar situation in FX options when you're long a deep-ITM American call on a positive-carry currency (say AUDJPY); you might find yourself so deep in the money, with so little time value left on the option, that you'd rather exercise the option and give up the remaining time value in return for the additional carry from getting the spot position early. Stock B could be considered to be more risky because it seems to be more volatile - sharp rises on large volume increases can easily be followed by sharp drops or by further rises in the start of a new uptrend.  However, if both A and B are trading on low volume in general, they can both be more on the risky side due to having relatively low liquidity, especially if you buy a large order compared to the average daily volume. But just looking at the criteria you have included in your question is not enough to determine which stock is riskier than the other, and you should look at this criteria in combination with other indicators and information about each stock to obtain a more complete picture. "At my soon to be legendary Stock Options Cafe, I recently wrote an article ""Betting On Apple at 9 to 2.""  It described a trade in which a 35% move in a stock over a fixed time (2 years) would result in a 354% gain in one's bet. In this case, the options serve to create remarkable leverage for speculators. In general, option help provide liquidity and extend the nature of the risk/reward curve.  There are option trades that range from conservative (e.g. a 'covered call') to wildly speculative, as the one I described above." Excellent, very sharp. No it will not be vega neutral exactly! If you think about it, what does a higher vol imply? That the delta of the option is higher than under BS model. Therefore, the vega should also be greater (simplistic explanation but generally accurate). So no, if you trade a 25-delta risky in equal size per leg, the vega will not be neutral. But, in reality, that is a very small portion of your risk. It plays a part, but in general the vanna position dominates by many many multiples.  What do you do that you asked such a question, if you don't mind? When volatility is higher, the option is more likely to end up in-the-money. Moreover, when it ends up in-the-money, it is likely to be over the strike price by a greater amount. Consider a call option. With high volatility, moves in the stock price are big - both up moves and down moves. If the stock moves up by a lot, the call option holder will benefit greatly. On the other hand, when the stock moves down, below a certain point the option holder does not care how big a down move the stock has. His downside is limited. Hence, the value of the option is increased by high volatility. I know everyone who searches this is looking for this answer. Bump so people are able to get this concept instead of looking all over the web for it. The answer is actually very simple: the cost of data. Seriously. Call the CBOE tomorrow and ask yourself. They have two big programs:  1) the penny pilot program, where options trade at penny increments instead of 5 cent increments. This is only extended to a select few symbols because of the amount of data this can generate is too much for the data vendors. Data vendors store and sell historical data. The exchanges themselves often have a big data vending business too. 2) the weekly options program, where only select symbols get these chains because of the amount of data they will generate. Liquidity and demand are factors in determining if the CBOE will consider enabling those series on new issues. (although they have to give the list of which symbols are on these programs to the SEC) The liquidity of options is really not a problem, as the option price is determined by the underlying price, and even if there was very little liquidity in the option itself, market makers are required to make a market at the price determined by the underlying. As long as the underlying has enough liquidity your slippage in trading the options should not be too much of a problem. You can read this ETO Market Making Scheme document for more details. If you are worried about an increase in volatility, then go long volatility. Volatility itself can be traded. Here in the US there is an index VIX that is described as tracking volatility. What VIX actually tracks is the premium of S&P 500 options, which become more expensive when traders want to hedge against volatility. In the US you can trade VIX options or invest in VIX tracking ETFs like VXX. Apparently there are similar ETFs listed in Canada, such as HUV. Volatility itself is quite volatile so it is possible that a small volatility long position would cover the losses of a larger long position in stocks. If you do choose to invest in a volatility ETF, be aware that they experience quite a lot of decay. You will not want to hold it for very long. I think if you are only trading stocks with average volume greater than 1M you should not have any trouble entering a 10,000 size trade. If you are you can try a couple of things: Change your order from a market order to a limit order, however this may potentially reduce the number of shares that are actually traded on that day, and you may miss out on some or all of your order. Limit your trading to more liquid stocks, say average daily volumes above 10M or 100M. Apart from that you might have to just put up with some extra slippage and incorporate it into your trading plan. That is you can reduce your R multiple to allow some slippage. I'd think that liquidity and speed are prioritized (even over retail brokers and in come cases over PoP) for institutional traders who by default have large positions.  When the going gets tough, these guys are out and the small guys - trading through average retail brokers - are the ones left holding the empty bag. 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.""" Ok, so disregarding passivity, could you help me through a simplified example?   Say I only had two assets, SPY and TLT, with a respective weight of 35 and 65% and I want want to leverage this to 4x.  Additionally, say daily return covar is:  * B/B .004% * B/S -.004% * S/S .02%   Now, if I read correctly, I should buy ATM calls xxx days in the future.  Which may look like: Ticker, S, K, Option Price, Delta, Lambda  * TLT  $126.04  $126.00  $4.35  0.50  14.5 * SPY  $134.91  $134.00  $6.26  0.55  11.8  ^ This example is pretty close but some assets are far off.   I feel like I'm on the wrong track so I'll stop here.    I just want to lever up my risk-parity. Margin rates are too high and I'm docked by Reg-T. The volume required to significantly move the price of a security depends completely on the orderbook for that particular security. There are a variety of different reasons and time periods that a security can be halted, this will depend a bit on which exchange you're dealing with. This link might help with the halt aspect of your question: https://en.wikipedia.org/wiki/Trading_halt The correct p/e for bp.l is 5.80. Bp.l is on the London stock exchange and prices are in local currency. The share price of 493 is reported in pence (not dollars). The EPS is reported in pounds. Using .85 pounds = 85 pence, you calculate the EPS as follows: 493.40/85 = 5.80 PE Yahoo totally screwed up. They converted the .85 pounds into US dollars ($1.34) but didn't convert the 493 pence. By using the 493 as dollars, they got 493.9/1.34 = 368 pe! Notice that Yahoo reports the American Depository Shares (symbol 'BP') with an EPS of $8.06. That correctly reflects that there are 6 shares of BP.l per ADS (1.34 * 6 = 8.04). But why is the share price listed at $46.69? Well...  493 GBp (pence) = 4.93 pounds 4.93 pounds  = 7.73 USD 7.73 USD * 6 shares per ADS = 46.38 USD