Why can't I short a particular stock?
In order to short a stock, you have to borrow the number of shares that you're shorting from someone else who holds the shares, so that you can deliver the shares you're shorting if it becomes necessary to do so (usually; there's also naked short selling, where you don't have to do this, but it's banned in a number of jurisdictions including the US). If a stock has poor liquidity, or is in high demand for shorting, then it may well be impossible to find anyone from whom it can be borrowed, which is what has happened in this instance.
"if you buy back the now ITM calls, then you will have a short term loss. That pair of transactions is independent, from a tax perspective, of your long position (which was being used as ""collateral"" in the very case that occurred). I can see your tax situation and can see the logic of taking a short term loss to balance a short term gain.  Referring to D Stanley's answer, #2 and #3 are not the same because you are paying intrinsic value in the options and the skew in #2, whereas #3 has no intrinsic value. Of course, because you can't know the future, the stock price could move higher or lower between #2 and #3. #1 presumes the stock continues to climb." "A 'Call' gives you the right, but not the obligation, to buy a stock at a particular price. The price, called the ""strike price"" is fixed when you buy the option. Let's run through an example - AAPL trades @ $259. You think it's going up over the next year, and you decide to buy the $280 Jan11 call for $12.  Here are the details of this trade. Your cost is $1200 as options are traded on 100 shares each. You start to have the potential to make money only as Apple rises above $280 and the option trades ""in the money."" It would take a move to $292 for you to break even, but after that, you are making $100 for each dollar it goes higher. At $300, your $1200 would be worth $2000, for example. A 16% move on the stock and a 67% increase on your money. On the other hand, if the stock doesn't rise enough by January 2011, you lose it all.  A couple points here - American options are traded at any time. If the stock goes up next week, your $1200 may be worth $1500 and you can sell. If the option is not ""in the money"" its value is pure time value. There have been claims made that most options expire worthless. This of course is nonsense, you can see there will always be options with a strike below the price of the stock at expiration and those options are ""in the money."" Of course, we don't know what those options were traded at.  On the other end of this trade is the option seller. If he owns Apple, the sale is called a ""covered call"" and he is basically saying he's ok if the stock goes up enough that the buyer will get his shares for that price. For him, he knows that he'll get $292 (the $280, plus the option sale of $12) for a stock that is only $259 today. If the stock stays under $280, he just pocketed $12, 4.6% of the stock value, in just 3 months. This is why call writing can be a decent strategy for some investors. Especially if the market goes down, you can think of it as the investor lowering his cost by that $12. This particular strategy works best in a flat to down market. Of course in a fast rising market, the seller misses out on potentially high gains.  (I'll call it quits here, just to say a Put is the mirror image, you have the right to sell a stock at a given price. It's the difference similar to shorting a stock as opposed to buying it.) If you have a follow up question - happy to help. EDIT - Apple closed on Jan 21, 2011 at $326.72, the $280 call would have been worth $46.72 vs the purchase price of $12. Nearly 4X return (A 289% gain) in just over 4 months for a stock move of 26%. This is the leverage you can have with options. Any stock could just as easily trade flat to down, and the entire option premium, lost." "First, two preliminaries, to address good points people made in comments. As AbraCadaver noted, before you move your $30k to something that might lose money, make sure you have enough cash to serve as an emergency fund in case you lose your income. Especially remember that big stock market crashes often go hand-in-hand with widespread layoffs. Also, you mentioned that you're maxed out in a 401k. As JoeTaxpayer hinted, this could very well already be invested in stocks, and, if it isn't, probably a big part of it should be. Regarding your $30k, you don't need to pay anybody. In general, fees and expenses can form a big drag on your investments, and it's good to avoid them as much as possible. In particular, especially with ""only"" $30k, it's unlikely that advisers can save you more than they cost. Also, all financial advisers have a cost: the ""free"" ones usually push you into investing in expensive funds that make them money at your expense. In that regard, keep in mind that, unlike a lawyer or a doctor, a financial adviser is not required by law to give advice that's in your best interest. When investing, there is a pretty short list of important considerations that you should keep in mind: (If anyone has any other points they think are similarly important, feel free to suggest an edit.) Practically speaking, I'd suggest investing in index funds. These are mutual funds that invest very broadly, in a ""passive"" way that doesn't spend a lot of effort (and money) trying to pick individual high-performing stocks or anything like that. Index funds provide a lot of diversification and tend to have low expense ratios. (Other, ""actively managed"" funds tend to be more expensive and often don't outperform index funds anyway.) If you're saving for retirement, there are even target date funds that are themselves composed of a small number of index funds (often domestic and international stocks and bonds), and will increase the proportion invested in bonds (safer) as they get closer to a target retirement date. See, for example the Vanguard Target Retirement 2045 fund. A fund like that one might be all you need if you are saving for retirement. Finally, you can invest online without paying any advisers. Not all companies are created equal, however; do your research. I personally highly recommend Vanguard, since they have a wide variety of no-load index funds and tend to have very low expense ratios. (No-load means you don't have to pay a fee to buy and sell.) Part of why they are inexpensive is that, unlike most financial companies, they are actually a cooperative owned by those who invest in their funds, so they don't need to try and milk a profit out of you. (Don't let that suggest that they're some ""small-potatoes hippie firm"", though: they're actually one of the largest.) I hope I helped. Keep posting if you have more questions!" The stock market is just like any other market, but stocks are bought and sold here. Just like you buy and sell your electronics at the electronics market, this is a place where buyers and sellers come together to buy and sell shares or stocks or equity, no matter what you call it. What are these shares?  A share is nothing but a portion of ownership of a company. Suppose a company has 100 shares issued to it, and you were sold 10 out of those, it literally means you are a 10% owner of the company. Why do companies sell shares? Companies sell shares to grow or expand. Suppose a business is manufacturing or producing and selling goods or services that are high in demand, the owners would want to take advantage of it and increase the production of his goods or services. And in order to increase production he would need money to buy land or equipment or labor, etc. Now either he could go get a loan by pledging something, or he could partner with someone who could give him money in exchange for some portion of the ownership of the company. This way, the owner gets the money to expand his business and make more profit, and the lender gets a portion of profit every time the company makes some. Now if the owner decides to sell shares rather than getting a loan, that's when the stock market comes into the picture. Why would a person want to trade stocks? First of all, please remember that stocks were never meant to be traded. You always invest in stocks. What's the difference? Trading is short term and investing is long term, in very simple language. It's the greed of humans which led to this concept of trading stocks. A person should only buy stocks if he believes in the business the company is doing and sees the potential of growth. Back to the question: a person would want to buy stocks of the company because: How does a stock market help society? Look around you for the answer to this question. Let me give you a start and I wish everyone reading this post to add at least one point to the answer. Corporations in general allow many people come together and invest in a business without fear that their investment will cause them undue liability - because shareholders are ultimately not liable for the actions of a corporation. The cornerstone North American case of how corporations add value is by allowing many investors to have put money towards the railroads that were built across America and Canada. For The stock market in particular, by making it easier to trade shares of a company once the company sells them, the number of people able to conveniently invest grows exponentially. This means that someone can buy shares in a company without needing to knock door to door in 5 years trying to find someone to sell to. Participating in the stock market creates 'liquidity', which is essentially the ease with which stocks are converted into cash. High liquidity reduces risk overall, and it means that those who want risk [because high risk often creates high reward] can buy shares, and those who want low risk [because say they are retiring and don't have a risk appetite anymore] can sell shares. "You have to read some appeals court cases see scholar.google.com , as well as SEC enforcement actions on sec.gov to get an understanding of how the SEC operates. http://www.sec.gov/spotlight/insidertrading/cases.shtml There are court created guidelines for how insider trading would be proven There is no clear line, but it is the ""emergency asset injunctions"" (freezing your assets if you nailed a suspiciously lucrative trade) you really want to avoid, and this is often times enforced/reported by the brokers themselves since the SEC does not have the resources to monitor every account's trading activities. There are some thin lines, such as having your lawyer file a lawsuit, and as soon as it is filed it is technically public so you short the recipient's stock. Or having someone in a court room updating you on case developments as soon as possible so you can make trades (although this may just be actually public, depending on the court). But the rules create the opportunities Also consider that the United States is the most strict country in this regard, there are tons of capital markets and the ideals or views of ""illegal insider trading"" compared to ""having reached a level of society where you are privileged to obtain this information"" vary across the board contains charts of countries where an existing insider trading prohibition is actually enforced: http://repository.law.umich.edu/cgi/viewcontent.cgi?article=1053&context=articles https://faculty.fuqua.duke.edu/~charvey/Teaching/BA453_2005/BD_The_world.pdf Finally, consider some markets that don't include equities, as trading on an information advantage is only applicable to things the SEC regulates, and there are plenty of things that agency doesn't regulate. So trying to reverse engineer the SEC may not be the most optimal use of energy" "Vitalik has mentioned this in a comment but I think it ought to be expanded upon: Companies that aren't already penny stocks really don't stand to gain anything from trying to prevent short interest.  Short selling does not inherently lower the stock price - not any more so than any other kind of selling.  When somebody shorts a stock, it's simply borrowed from another investor's margin; as long as it's not a naked short resulting in an FTD (Failure To Deliver) then it does not add any ""artificial"" selling pressure. In fact, shorting can actually drive the price up in the long term due to stops and margin calls.  Not a guarantee, of course, but if a rally occurs then a high short interest can cause a cascade effect from the short ""squeeze"", resulting in an even bigger rally than what would have occurred with zero short interest.  Many investors actually treat a high short interest as a bullish signal. Compare with margin buying - essentially the opposite of short selling - which has the opposite effect.  If investors buy stocks on margin, then if the value of that stock decreases too rapidly they will be forced to sell, which can cause the exact same cascade effect as a short interest but in the opposite direction.  Shorting is (in a sense) evening out the odds by inflating the buying pressure at lower stock prices when the borrowers decide to cover and take profits. Bottom line is that, aside from (illegal) insider trading, it doesn't do businesses any good to try to manipulate their stock price or any trading activity.  Yes, a company can raise capital by selling additional common shares, but a split really has no effect on the amount of capital they'd be able to raise because it doesn't change the actual market cap, and a dilution is a dilution regardless of the current stock price.  If a company's market cap is $1 billion then it doesn't matter if they issue 1 million shares at $50.00 each or 10 million shares at $5.00 each; either way it nets them $50 million from the sale and causes a 5% dilution, to which the market will react accordingly. They don't do it because there'd be no point." This is a gross simplification as there are a few different ways to do this. The principle overall is the same though. To short a stock, you borrow X shares from a third party and sell them at the current price. You now owe the lender X shares but have the proceeds from the sale. If the share price falls you can buy back those shares at the new lower price, return them to the lender and pocket the difference. The risk comes when the share price goes the other way, you now owe the lender the new value of the shares, so have to find some way to cover the difference. This happened a while back when Porsche made a fortune buying shares in Volkswagen from short sellers, and the price unexpectedly rose. "To summarize, there are three basic ways: (3) is the truly dangerous one. If there is a lot of short interest in a stock, but for some reason the stock goes up, suddenly a lot of people will be scrambling to buy that stock to cover their short position -- which will drive the price up even further, making the problem worse.  Pretty soon, a bunch of smart rich guys will be poor guys who are suddenly very aware that they aren't as smart as they thought they were.  Eight years ago, such a ""short squeeze"", as it's called, made the price of VW quadruple in two days.  You could hear the Heinies howl from Hamburg to Haldenwanger. There are ways to protect yourself, of course.  You can go short but also buy a call at a much higher price, thereby limiting your exposure, a strategy called a ""straddle"", but you also reduce your profit if you guessed right. It comes down to, as it always does, do you want to eat well, or to sleep well?"