How do straddles that involve selling options protect against early assignment?
Yes, that's the risk. If the stock is bouncing around a lot your options could get assigned.  If it heads south you now are the proud owner of more of a falling stock.  It's good that you're looking to understand the risks of an investment method.  That's important no matter what the method is.
I believe the answer is that to protect yourself it is good to get credit protection so you will be notified when new credit is taken in your name.   Also, you can use http://www.annualcreditreport.com/ to look at your credit report. HINT:  While you do that, and while you are in the TransUnion report, you will have the option to DISPUTE adverse items.   I always suggest that people dispute everything adverse.  That puts the onus on the other parties to produce evidence to TransUnion within 30 days attesting to the validity of the adverse item.   You would be surprised how many will simply drop off your report after doing that.  Everybody should do this Here is a direct address for TransUnion: https://dispute.transunion.com/dp/dispute/landingPage.jsp ==>  Once the disputes are finalized, the results get communicated to the other two bureaus. It is amazing how well it works.  It can raise your credit score significantly. It really helps to watch your credit report yourself, and also to get whatever protection is offered that may help protect you against others opening new accounts in your name. I cannot explain how the derivative is created in specific, because I have never actually built one. However, [Investopedia](http://www.investopedia.com/terms/m/mitts.asp#axzz1wwZTADu5) suggests to me that the concept is quite simple. They are selling a synthetic protective put.   An individual could quite easily remake the payout structure of these securities -  1. Buy the share or index in which you are interested 2. Buy a put option on the same asset with a strike price as your purchase price 3. If you are interested in the target-term aspect, you ought to buy European puts. American options will be more expensive, but give you more flexibility to sell your share. 4. At the maturity of your option, if the share is below the price you paid you can exercise your option and still have your principal. If it is above, leave your option alone and sell your share for profit. "You're forgetting the fundamental issue, that you never have to actually exercise the options you buy.  You can either sell them to someone else or, if they're out of the money, let them expire and take the loss. It isn't uncommon at all for people to buy both a put and call option (this is a ""straddle"" when the strike price of both the put and call are the same). From Investopedia.com: A straddle is an options strategy in which the investor holds a position in both a call and put with the same strike price and expiration date, paying both premiums. This strategy allows the investor to make a profit regardless of whether the price of the security goes up or down, assuming the stock price changes somewhat significantly.   Read more: Straddle http://www.investopedia.com/terms/s/straddle.asp#ixzz4ZYytV0pT" You can buy a put and exercise it. The ideal option in this case will have little time premium left and very near the money. Who lent you the shares? The person that sold you the option! In reality, when you exercise,  assignment can be random, but everything is [supposedly] accounted for as the option seller had to put up margin collateral to sell the option. hmmm. I think it's because in both cases, you must pay for it up front, before the positions are closed out. You own nothing except the right to buy the stock re: the call, and the obligation to buy the stock re: the short.  You buy a call, but must borrow the stock, for which you must put some margin collateral and there is a cost to borrow. You pay for that, of course.  I wouldn't call it lending though. You typically need to specify that you want the GTC order to be working during the Extended hours session. I trade on TD Ameritrade's Thinkorswim platform, and you can select DAY, GTC, EXT or GTC_EXT. So in your case, you would select GTC_EXT. "What is being described in Longson's answer, though helpful, is perhaps more similar to a financial spread bet. Exactly like a bookmaker, the provider of a spread bet takes the other side of the bet, and is counter party to your ""trade"". A CFD is also a bet between two parties. Now, if the CFD provider uses a market maker model, then this is exactly the same as with a spread bet and the provider is the counter party. However, if the provider uses a direct market access model then the counter party to your contract is another CFD trader, and the provider is just acting as an intermediary to bring you together (basically doing the job of both a brokerage and an exchange). A CFD entered into through a direct market access provider is in many ways similar to a Futures contract. Critically though, the contract is traded 'over-the-counter' and not on any centralized and regulated exchange. This is the reason that CFDs are not permitted in the US - the providers are not authorized as exchanges. Whichever model your CFD provider uses, it is best to think of the contract as a 'bet' on the future price movements of the underlying stock or commodity, in much the same way as with any other derivative instrument such as futures, forwards, swaps, or options. Finally, note that because you don't actually own the underlying stock (just as Longson has highlighted) you won't be entitled to any of the additional benefits that can come with ownership of a stock, such as dividend payments or the right to attend shareholder meetings. RESPONSE TO QUESTION So if I understand correctly, the money gained through a direct market access model comes from other investors in the same CFD who happened to have invested in the ""wrong"" direction the asset was presumed to take. What happens then, if no one is betting in the opposite direction of my investment. Your understanding is correct. If literally nobody is betting in the opposite direction to you, then you will not be able to trade. This is true for any derivative market; if suddenly every single buyer were to remove their bids from the S&P futures, then no seller would be able to sell. This is a very extreme scenario, as the S&P futures market is incredibly liquid (loads of buyers and sellers at all times).  However, if something like this does happen (the flash crash of 2010, for example), then the centralized futures exchanges such as the CME have safeguards in place - the market become locked-limit so that it can only fall so far, there may be no buyers below the lock limit price, but the market cannot fall through it. CFD providers are not obliged to provide such safeguards, which is why regulators in the US don't permit them to operate. It may be the case that if you're trying to buy a CFD for a thinly traded and ill-liquid stock there will be no seller available. One possibility is that the provider will offer a 'hybrid' model, and in the absence of an independent counter party they will take the opposite side of your bet, and then offset their risk by taking an opposing position in the underlying stock." "You're forgetting the fundamental issue, that you never have to actually exercise the options you buy.  You can either sell them to someone else or, if they're out of the money, let them expire and take the loss. It isn't uncommon at all for people to buy both a put and call option (this is a ""straddle"" when the strike price of both the put and call are the same). From Investopedia.com: A straddle is an options strategy in which the investor holds a position in both a call and put with the same strike price and expiration date, paying both premiums. This strategy allows the investor to make a profit regardless of whether the price of the security goes up or down, assuming the stock price changes somewhat significantly.   Read more: Straddle http://www.investopedia.com/terms/s/straddle.asp#ixzz4ZYytV0pT"