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.
"The margin rules are also more complicated.  A simple buy on a non-margin account will never run into margin rules and you can just wait out any dips if you have confidence the stock will recover.  A ""simple"" short sell might get you a call from your broker that you have a margin call, and you can't wait it out without putting more money in.  Personally I have trouble keeping the short sale margin rules straight in my head, at least compared to a long sale. I got in way over my head shorting AMZN once, and lost a lot of money because I thought it was overvalued at the time, but it just kept going up and I wanted it to go down.   I've never gotten stuck like that on a long position." When you buy a stock, the worst case scenario is that it drops to 0.  Therefore, the most you can lose when buying a stock is 100% of your investment. When you short a stock, however, there's no limit on how high the stock can go.  If you short a stock at 10, and it goes up to 30, then you've lost 200% on your investment.  Therefore shorting stocks is riskier than buying stocks, since you can lose more than 100% of your investment when shorting. because the price might go up, but it will never be as big of a change as a regular price drop i suppose... That is not true.  Stocks can sometimes go up significantly (50-100% or more) in a very short amount of time on a positive news release (such as an earnings or a buyout announcement).  A famous example occurred in 2008, when Volkswagen stock quintupled (went up 400%) in less than 2 days on some corporate news: Porsche, for some reason, wants to control Volkswagen, and by building up its stake has driven up the price. Hedge funds, figuring the share price would fall as soon as Porsche got control and stopped buying, sold a lot of VW shares short. Then last weekend, Porsche disclosed that it owned 42.6 percent of the stock and had acquired options for another 31.5 percent. It said it wanted to go to 75 percent. The result: instant short-squeeze. The German state of Lower Saxony owns a 20 percent stake in VW, which it said it would not sell. That left precious few shares available for anyone else. The shorts scrambled to cover, and the price leaped from about €200, or about $265, to above €1,000. Overvalued does not mean an opportunity to short.  As long as a company's earnings are decent and there are limited other opportunities in the market, a stock would stay overvalued. its just that future returns on the stock might be limited. For shorting you need an expected trigger. Say you expect an overvalued company's earnings to decline or significantly miss expectations. This would be a candidate for shorting.. While I am not an advocate of shorting anything (unlimited downside, capped upside), you can: Okay- I follow that.    When we look a shorting a name -  what makes that an equity transaction rather than a debt one? I guess how does that differ from investing in a bond?    I recognize the simplicity of this question.    Thanks. Is it because the non-public info isn't directly related to the holding?   Seems like it should be illegal. If Congress was going to write a bill let's say that bans the use of oil in America, and 10 days before they release the bill to the public, 6 members of congress short oil stocks. Seems illegal to me. The trades after that date were Ex-DIV, meaning after 5 pm Dec 12, new trades did not include the shares that were to be spun out.  The process is very orderly, no one pays $60 without getting the spinoff, and no one pays $30 but still gets it. The real question is why there's that long delay nearly three weeks to make the spinoff shares available. I don't know.  By the way, the stock options are adjusted as well. Someone owning a $50 put isn't suddenly in the money on 12/13. Edit - (I am not a hoarder. I started a fire last night and realized I had a few Barron's in the paper pile) This is how the ABT quote appeared in the 12/24 issue of Barron's. Both the original quote, and the WI (when issued) for the stock less the spin off company. That's because they literally could not help you. It's not that they were just unwilling to. A hedge fund manager might be able to do it, because the person who bet on Facebook would be willing to let him borrow their shares.  An IPO in explain like I'm five:  A bank helps underwrite the shares pre offering. This means they buy the shares wholesale. They buy a large majority of the company in order to offer them to the public when the stock goes public. The bank does this for profit, the company does this become it helps raise their price. The bank that underwrites the stock is legally prohibited from short selling that stock for ***at least***  30 days before the IPO. This is to prevent the bank from trying to commit fraud by selling stock out the front door and betting against it out the back.   ***  So, now let's jump forward to the day of the IPO. The bank is offering stock to everyone who wants to buy it (other banks who will cut it up and sell it to more people). In order to short the stock someone must be willing to let you borrow their shares. Only the bank that underwrote it prohibited from short selling. It's possible but hard. The underwriter has the majority of the shares for the first thirty days anyways. They're just going to release enough of them to raise volume on the ticker symbol (volume is the amount of people buying and selling). The others the underwriter sold to are unwilling to let someone borrow their stock because they want to ride the price hike and shares are in short supply. So while it's possible to short shares, it's very hard. The underwriters limit the supply of shares to prevent that from happening. The underwriters can't just let you short their own shares because they are legally prohibited from it.   Basically, you're left with the fact that the only person who has enough supply to let you short, is prohibited by law from letting you do it. I'm sure Morgan Stanley would have been happy to let their customers short Facebook (as long as you did it through them) to hedge their bets. But they can't. "&gt; It just has to finish below the strike price of the short (which can be higher than the stock's current price).  You're talking about a put option.   That's one ""short"" strategy, but it's not shorting a stock, so the terminology is a little jumbled.   There are reasons to not do straight options, because they can be quite risky, and you have to get the time frame correct." In terms of pricing the asset, this functions in exactly the same way as a regular sell, so bids will have to be hit to fill the trade. When shorting an equity, currency is not borrowed; the equity is, so the value of per share liability is equal to it's last traded price or the ask if the equity is illiquid. Thus when opening a short position, the asks offer nothing to the process except competition for your order getting filled. Part of managing the trade is the interest rate risk.  If the asks are as illiquid as detailed in the question, it may be difficult even to locate the shares for borrowing. As a general rule, only illiquid  equities or those in free fall may be temporarily unable for shorting. Interactive Brokers posts their securities financing availabilities and could be used as a proxy guide for your broker. But by closing the short position the broker would still be purchasing shares from the market no? Or at least, someone would be purchasing the shares to close the short position. So, why doesn't the broker just let Client A keep their short position open and buy shares in the market so that Client B can sell them...I know it sounds a bit ridic, but not much more so to me than letting Client A borrow the shares to begin with! &gt; I shorted it the moment it opened for trading at $42 dollars a share.  Now this is a shady part of the capital markets and the preferred treatment some investors get. Technically, you shouldn't be able to short stocks until 3 days after it starts trading because the trades don't settle for three days and only then should you be able to borrow the stock. But, big brokers and banks can cover managers they have good relations with and let them borrow the shares to short it. Your question has 6 questions marks along with comments on what you'd like to know.  Yes, there are stocks that are tough to short, a combination of low float, high current short positions, etc. Interest charged on the position rises in a supply/demand fashion.  To unwind the position, there's always going to be stock available to buy. A shortage of willing sellers will cause the price to go up, but you'll see a bid/ask and the market will clear, i.e. The buy order fills. In India the only way to short a stock is using F&O which I personally find to be sufficient for any shorting needs. However, Futures can be generally sold for upto 3 months but options have more choices which are even upto 5 years you can buy a put of a longer duration and when you want to do buy-back, you can directly sell the same option by squaring-off the trade before expiry date. You generally get approximately the same profit as shorting but you get to limit your risk. "If you can't find anyone to lend you the shares, then you can't short. You can attempt to raise the interest rate at which you will borrow at, in order to entice others to lend you their shares. In practice, broadcasting this information is pretty convoluted. If there aren't any stocks for you to buy back, then you have to buy back at a higher price. As in, place a limit buy order higher and higher until someone decides to sell to you. This affects your profit. Regarding the public ledger: This functions different in different markets. United States stock markets have an evolving body of regulations to alleviate the exact concerns you detailed, but Canada's or Dubai's stock markets would have different provisions. You make the assumption that it is an efficient process, but it is not and it is indeed ripe for abuse. In US stocks, the public ledger has a 3 business day delay between showing change of ownership. Many times brokers and clearing firms and other market participants allow a customer to go short with fake shares, with the idea that they will find real shares within the 3 business day time period to cover the position. During the time period that there is no real shares hitting the market, this is called a ""naked short"". The only legal system that attempts to deter this practice is the ""fail to deliver"" (FTD) list. If someone fails to deliver, that means there is a short position active with fake shares for which no real shares have been borrowed against. Too many FTD's allow for a short selling restriction to be placed, meaning nobody else can be short, and existing short sellers may be forced to cover."