Deriving the put-call parity
Think of it this way: C + (-P) = forward contract. Work it out from there. Anyways, this stack is meant for professionals, not students, I think.
They are actually pretty common and it's the reason that anyone who takes a Board seat at a company without D&amp;O insurance is playing russian roulette.  Now winning a shareholder suit on the merits (whether personal or derivative liability) is a whole different story - at least in Delaware Chancellery (fun fact DE has two judicial systems, one for corporate stuff with world class talent and one for everything else).    There's this doctrine called the 'Business Judgment Rule' which is a very high bar for a shareholder to overcome. Otherwise you'd see shareholder suits for every business deal that went wrong.  The other problem these Uber investors might run into is they haven't realized a loss, nor are they likely to have a negative return on the initial investment. Marking down a gain against a high water mark is an uphill battle.  Based on what it public, idk the cause of action, maybe Kalanick is going back on contractual language in his separation agreement (which is currently non-public) or that some of his actions as CEO could be considered self-dealing (again, not information currently in the public domain). Or maybe it's just a threat to put all the non-public shitty things he has done in a pleading and therefore put it in the public domain. 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. "A derivative contract can be an option, and you can take a short (sell) position , much the same way you would in a stock. When BUYING options you risk only the money you put in. However when selling naked(you don't have the securities or cash to cover all potential losses) options, you are borrowing. Brokers force you to maintain a required amount of cash called, a maintenance requirement. When selling naked calls - theoretically you are able to lose an INFINITE amount of money, so in order to sell this type of options you have to maintain a certain level of cash in your account. If you fail to maintain this level you will enter into whats often referred to as a ""margin-call"". And yes they will call your phone and tell you :). Your broker has the right to liquidate your positions in order to meet requirements. PS: From experience my broker has never liquidated any of my holdings, but then again I've never been in a margin call for longer then a few days and never with a severe amount. The margin requirement for investors is regulated and brokers follow these regulations." They are actually both undergraduate texts; however, Investments is FAR more complex.   Essentials of Investments really waters down the statistical and mathematical notation while Investments does not.  Investments also has an entire section (4-5 chapters) called options, futures, and other derivatives while Essentials of Investments does not.   [Of course, if you want to learn about options, futures, and other derivatives, there is a seminal book by John Hull with that exact title.] That notwithstanding, neither book is sophisticated enough to be considered a true graduate school textbook in quantitative investment theory.  No grad schools worth their salt are going to rely too heavily on Investments in a specialized finance curriculum.   It's a great book to start out, though. Not to be a jerk, since I'm learning about options myself, but I think you have a few things wrong about your tesla put postion.  First, assuming it was itm or atm within a week of strike it would maybe be worth $12-15, I glanced at the 11/10 put strikes ~325 trades for $12.65 https://www.barchart.com/stocks/quotes/TSLA/options?expiration=2017-11-10  The closer it gets to expiry theta decay reduces put value significantly, the 325's that expire tomorrow are only worth $2.60.   Expecting TSLA to drop from 325 to 50 a share by Jan has a .006% chance of occuring according to the current delta. It's a lottery ticket at best.  _____ Lastly the $50 price is the expected share price at the date of expiry. The price you pay is 57c for the options. So in order to get to your 494k number TSLA would need to decline $50 dollars to a price of 275 a share. You wouldn't want to buy 50 dollar puts, just the 275 puts, provided it declines very quickly.   EDIT: I was looking at the recent expiration to get an idea of atm or itm prices, since it's not like you would hold to expiration. Also the Jan has a 0.6% chance of hitting 50, not .006%. That said what I've noticed when things start to slide is that puts have a weird way of pricing themselves. For example when something gradually goes up all of the calls go up down the chain through time frames, but puts do not in the same fashion. Further out lower priced puts won't move nearly as much unless the company is basically headed for bankruptcy. 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. In the money puts and calls are subject to automatic execution at expiration. Each broker has its own rules and process for this.  For example, I am long a put. The strike is $100. The stock trades at the close, that final friday for $90. I am out to lunch that day. Figuratively, of course. I wake up Saturday and am short 100 shares. I can only be short in a margin account. And similarly, if I own calls, I either need the full value of the stock (i.e. 100*strike price) or a margin account.  I am going to repeat the key point. Each broker has its own process for auto execution. But, yes, you really don't want a deep in the money option to expire with no transaction.  On the flip side, you don't want to wake up Monday to find they were bought out by Apple for $150. "The question you are asking concerns the exercise of a short option position.  The other replies do not appear to address this situation. Suppose that Apple is trading at $96 and you sell a put option with a strike price of $95 for some future delivery date - say August 2016.  The option contract is for 100 shares and you sell the contract for a premium of $3.20. When you sell the option your account will be credited with the premium and debited with the broker commission.  The premium you receive will be $320 = 100 x $3.20.  The commission you pay will depend on you broker. Now suppose that the price of Apple drops to $90 and your option is exercised, either on expiry or prior to expiry.  Then you would be obliged to take delivery of 100 Apple shares at the contracted option strike price of $95 costing you $9,500 plus broker commission.  If you immediately sell the Apple shares you have purchased under your contract obligations, then assuming you sell the shares at the current market price of $90 you would realise a loss of $500 ( = 100x($95-$90) )plus commission.  Since you received a premium of $320 when you sold the put option, your net loss would be $500-$320 = $180 plus any commissions paid to your broker. Now let's look at the case of selling a call option.  Again assume that the price of Apple is $96 and you sell a call option for 100 shares with a strike price of $97 for a premium of $3.60.  The premium you receive would be $360 = 100 x $3.60.  You would also be debited for commission by your broker. Now suppose that the price of Apple shares rises to $101 and your option is exercised.  Then you would be obliged to deliver 100 Apple shares to the party exercising the option at the contracted strike price of $97.  If you did not own the shares to effect delivery, then you would need to purchase those shares in the market at the current market price of $101, and then sell them to the party exercising the option at the strike price of $97.  This would realise an immediate loss of $400 = 100 x ($101-$97) plus any  commission payable.  If you did own the shares, then you would simply deliver them and possibly pay some commission or a delivery fee to your broker.  Since you received $360 when you sold the option, your net loss would be $40 = $400-$360 plus any commission and fees payable to the broker. It is important to understand that in addition to these accounting items, short option positions carry with them a ""margin"" requirement.  You will need to maintain a margin deposit to show ""good faith"" so long as the short option position is open.  If the option you have sold moves against you, then you will be called upon to put up extra margin to cover any potential losses."