Large volume options sell
It depends upon who the counterparty is. If the counterparty is the OCC, they would most likely call force majeure if their finances were at serious risk.  They could be forced to take a loss but not to be pulled apart.  Villain could always try to take the OCC to court, but then his plot would probably be exposed in discovery. The need to involve the courts is even greater if these are private contracts. If the options were on one security, they would be difficult to sell in one day.  If they were spread across the most liquid ETFs and equities, they could be sold in one day easily, the above solvency problems notwithstanding. "Yes this is possible in the most liquid securities, but currently it would take several days to get filled in one contract at that amount There are also position size limits (set by the OCC and other Self Regulatory Organizations) that attempt to prevent people from cornering a market through the options market. (getting loads of contacts without effecting the price of the underlying asset, exercising those contracts and suddenly owning a huge stake of the asset and nobody saw it coming - although this is still VERY VERY possible) So for your example of an option of $1.00 per contract, then the position size limits would have prevented 100 million of those being opened (by one person/account that is). Realistically, you would spread out your orders amongst several options strike prices and expiration dates. Stock Indexes are some very liquid examples, so for the Standard & Poors you can open options contracts on the SPY ETF, as well as the S&P 500 futures, as well as many other S&P 500 products that only trade options and do not have the ability to be traded as the underlying shares. And there is also the saying ""liquidity begets liquidity"", meaning that because you are making the market more liquid, other large market participants will also see the liquidity and want to participate, where they previously thought it was too illiquid and impossible to close a large position quickly"
I think that assuming that you're not looking to trade the fund, an index Mutual Fund is a better overall value than an ETF. The cost difference is negligible, and the ability to dollar-cost average future contributions with no transaction costs. You also have to be careful with ETFs; the spreads are wide on a low-volume fund and some ETFs are going more exotic things that can burn a novice investor. Track two similar funds (say Vanguard Total Stock Market: VTSMX and Vanguard Total Stock Market ETF: VTI), you'll see that they track similarly.  If you are a more sophisticated investor, ETFs give you the ability to use options to hedge against declines in value without having to incur capital gains from the sale of the fund. (ie. 20 years from now, can use puts to make up for short-term losses instead of selling shares to avoid losses)  For most retail investors, I think you really need to justify using ETFs versus mutual funds. If anything, the limitations of mutual funds (no intra-day trading, no options, etc) discourage speculative behavior that is ultimately not in your best interest. EDIT: Since this answer was written, many brokers have begun offering a suite of ETFs with no transaction fees. That may push the cost equation over to support Index ETFs over Index Mutual Funds, particularly if it's a big ETF with narrow spreads.. "Whether or not you make money here depends on whether you are buying or selling the option when you open your position.  You certainly would not make money in the scenario where you are buying options at the open.  If fact you would end up loosing quite a lot of money. You do not specify whether you are buying or selling the options, so let's assume that you are buying both the call and the put.  We'll look a profitable trade at the bottom of my answer. Buying an in-the-money Call option with a strike price of $90 when the underlying asset price is $150 would cost you a small fraction over $6000 = (100 x $60) since the intrinsic value value of the option is $60.  Add to this cost any commission charged by your broker. Buying an out-of-the-money Put option with a strike price of $110 when the underlying asset price is $150 would cost you a ""small"" premium - lets say a premium of something like $0.50.  The option has no intrinsic value, only time value and a volatility value, so the exact cost would depend on the time to expiry and the implied volatility of the underlying asset. Since the strike price is ""well out of the money"", being about 27% below the underlying asset price, the premium would be small.  So, assuming the premium of $0.50, you would pay $50 for the option plus any commission applicable. The cash settlement on expiry, with an underlying settlement price of $100, would be a premium of $10 for each of the two options, so you would receive cash of 100 x ($10 + $10) = $2000, less any commission applicable.  However, you have paid $6000 + $50 to purchase the options, so you realise a net loss of $6050 - $2000 = $4050 plus any commissions applicable. Thus, you would make a profit on the put option, but you would realise a very large loss on the call option. On the other hand, if you open your position by selling the call option and buying the put option, then you would make money. For the sale of the call option you would receive about $6000.  For the purchase of the put option you would pay about $50. On settlement, you would pay $1000 to buy back the call option and you would receive about $1000 when selling the put option. Thus you net profit would be about ($6000 - $1000) for the call position, and ($1000 - $50) for the put position.  The net profit would then total $5950 less an commissions payable." Previously, advertisement volumes were not allowed to be louder than the peak volume (as opposed to the average volume) of the corresponding show. Obviously, the loudest point of a show isn't immediately before the commercial break, so the difference in sounds was very large.   This new regulation should change things for the better. However, I can see TV content producers putting very quiet parts right before breaks to maintain the difference in volume that advertisers rely on to draw attention. The liquidity primarily depends on the specific equity type / position you are looking at. You want to look for stocks or ETFs that have significant volume themselves before trying to jump into an option contract. The most important things you should look at are Volume and Open Interest for the specific contracts, strikes, and expiration. Near the money / in the money contracts from near term expiration tend to have the highest liquidity and the smallest (relative) spreads. 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. Just a few observations within the Black-Scholes framework: Next, you can now use the Black-Scholes framework (stock price is a Geometric Brownian Motion, no transaction costs, single interest rate, etc. etc.) and numerical methods (such as a PDE solver) to price American style options numerically, but not with a simple closed form formula (though there are closed-form approximations). Something really does seem seedy that if I invest $2500, that I'll make above 50k if the stock doubles. Is it really that easy? You only buy or sell on margin. Think of when the stock moves in the opposite direction. You will loose 50k. You probably didn't look into that. Investment will vanish and then you will have debt to repay. Holding for long term in CFD accounts are charged per day. Charges depends on different service providers. CFD isn't and should not be used for long term. It is primarily for trading in the short term, maybe a week at the maximum. Have a look at the wikipedia entry and educate yourself. Well the thing to understand about HFT is that the volume levels heavily affect not just the earnings but also the ecosystem. HFT is almost always liquidity constrained so the volume and volatility is going to affect the overall profitability of the strategy since less of these things means fewer and smaller trading opportunities.  Since 2008 volume and volatility have been heavily negatively correlated with risk-on/risk-off. During risk-off periods investors seem to panic and trading hits a frentic pace. This describes late 2008 and more recently August 2011. Even in 2012 the highest volume/volatility period was in May when the Euro deals were in danger. Risk-on environments tend to be marked be calm, orderly buying.  Second the dark pool issue is bringing liquidity out of the lit markets where HFT normally makes its money. The primary reason for this trend is that dark pools are allowed to offer sub-penny quotes whereas lit exchanges are not. Because of this arbitrary regulatory constraint most of the time dark pools are going to offer better prices, especially on thick book securities.  But beyond that the level of volume effects some HFT players more heavily then others. Imagine all the HFT firms as a pride of lions. When volume is high and liquidity is flowing it's like the pride has brought in a giant water buffalo. The biggest, baddest cats eat first, but there's still food left for the cubs after they're finished feeding.  But if the pride only brings in say a baby gazelle the alpha cats will eat everything and the runts will go hungry. That basically describes what's happening now. A firm like RennTech or GETCO will make less money in a low volume environment, but still do fine. Marginal firms like Eladian will lose the ability to make any money.  Since the marginal firms need the press and the dominant firms tend to be more secretive than the NSA, you'll tend to read more about the former than the latter.