Borrowed shares how are they tracked?
Brokerage firms are required to report the number of shares being shorted.  This information is reported to the exchange (NYSE of NASDAQ) and is made public.  Most financial sites indicate the number of shares being shorted for a particular stock.  The image below from Yahoo finance shows 3.29 million shares of CMG were being shorted at the close of 9-28-2012.  This is over 12% of the total outstanding shares of CMG.  For naked short selling additional information is tracked.  If the brokerage is unable to borrow shares to deliver before the settlement date of a short sale then the transaction is recorded as fails-to-deliver.  No money or shares are exchanged since the brokerage is unable to deliver the shares that were agreed upon.  A large amount of fails-to-deliver transactions for a stock usually indicates an excessive amount of naked shorting.  When investors and brokerage firms start to aggressively short a stock they will do so without having borrowed the shares to sell.  This will result in a large amount of naked short selling.  When there are a large number of naked short sellers not all the sellers will be able to borrow the necessary shares before the settlement date and many fails-to-deliver transactions will be recorded. The SEC records the number of fails-to-deliver transactions. The table below summarizes the fails-to-deliver transactions from 1-1-2012 through 9-14-2012 (data obtained from here). The “Ext Amount” column shows the total dollar value of the transactions that failed ( i.e. Fail Qty * Share price ).  The “Volume” column is the total number of shares traded in the same time period.  The “% Volume” shows the percentage of shares that failed to deliver as a percentage of the total market volume. The table orders the data in descending order by the quantity of shares that were not delivered.  Most of the companies at the top of the list no longer exist.  For many of these companies, the quantity of shares that failed to deliver where many multiples of the number of shares traded during the same time period.  This indicates massive naked short selling as many brokerages where unable to find shares to borrow before the settlement date. More information here.
To expand on the comment made by @NateEldredge, you're looking to take a short position.  A short position essentially functions as follows:  Here's the rub: you have unlimited loss potential.  Maybe you borrow a share and sell it at $10.  Maybe in a month you still haven't closed the position and now the share is trading at $1,000.  The share lender comes calling for their share and you have to close the position at $1,000 for a loss of $990.  Now what if it was $1,000,000 per share, etc. To avoid this unlimited loss risk, you can instead buy a put option contract.  In this situation you buy a contract that will expire at some point in the future for the right to sell a share of stock for $x.  You get to put that share on to someone else. If the underlying stock price were to instead rise above the put's exercise price, the put will expire worthless — but your loss is limited to the premium paid to acquire the put option contract. There are all sorts of advanced options trades sometimes including taking a short or long position in a security.  It's generally not advisable to undertake these sorts of trades until you're very comfortable with the mechanics of the contracts.  It's definitely not advisable to take an unhedged short position, either by borrowing someone else's share(s) to sell or selling an option (when you sell the option you take the risk), because of the unlimited loss potential described above. "Do not use a shared bank account.  One of you can cash/deposit the check in your personal account and then either pay the others in the group cash or write them a check.  You open yourself up to many, many problems sharing a bank account and/or money.  Treat it like a business as far as income goes, but I would not recommend any type of formal business, LLC, partnership, sole proprietorship, etc. For federal taxes, you just keep track of how much ""you"" personally are paid and report that at the end of the year as income, most likely on a 1040EZ 1040SE, along with any other income you have." 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. "To add on to the other answers, in asking why funds have different price points one might be asking why stocks aren't normalized so a unit price of $196 in one stock can be directly compared to the same price in another stock.  While this might not make sense with AAPL vs. GOOG (it would be like comparing apples to oranges, pun intended, not to mention how would two different companies ever come to such an agreement) it does seem like it would make more sense when tracking an index.  And in fact less agreement between different funds would be required as some ""natural"" price points exist such as dividing by 100 (like some S&P funds do). However, there are a couple of reasons why two different funds might price their shares of the same underlying index differently. Demand - If there are a lot of people wanting the issue, more shares might be issued at a lower price.  Or, there might be a lot of demand centered on a certain price range. Pricing - shares that are priced higher will find fewer buyers, because it makes it harder to buy round lots (100 shares at $100/share is $10,000 while at $10/share it's only $1000).  While not everyone buys stock in lots, it's important if you do anything with (standardized) options on the stock because they are always acting on lots.  In addition, even if you don't buy round lots a higher price makes it harder to buy in for a specific amount because each unit share has a greater chance to be further away from your target amount. Conversely, shares that are priced too low will also find fewer buyers, because some holders have minimum price requirements due to low price (e.g. penny) stocks tending to be more speculative and volatile. So, different funds tracking the same index might pick different price points to satisfy demand that is not being filled by other funds selling at a different price point." "To Many question and they are all treated differently. I was wondering how the logistics of interest and dividend payments are handled on assets , such as mortgages, bonds, stocks,   What if the owner is some high-frequency algorithm that buys and sells bonds and stocks in fractions of a second? When the company decides to pay dividends, does it literally track   down every single owner of that stock and deposit x cents per share in   that person's bank account? (This sounds absolutely absurd and seems   like it would be a logistical nightmare). In Stocks, the dividends are issued periodically. The dividend date is declared well in advance. As on end of the day on Dividend date, the list of individuals [or entities] who own the stock is available with the Stock-Exchange / Registrar of the companies. To this list the dividends are credited in next few days / weeks via banking channel. Most of this is automated. What if the owner is some high-frequency algorithm that buys and sells bonds and stocks in fractions of a second? On bonds, things work slightly differently. An Bond is initially issued for say 95 [discount of 5%] and payment of 100 after say 5 years. So when the person sells it after an year, he would logically look to get a price of 96. Of course there are other factors that could fetch him a price of 94.50 or 95.50. So every change in ownership factors in the logical rate of interest. The person who submits in on maturity gets 100.  For the homeowner, I'm assuming he / she still makes mortgage payments to the initial bank they got the mortgage from, even if the bank no longer ""owns"" the mortgage. In this case, does the trader on the secondary market who owns the mortgage also come back to that bank to collect his interest payment? This depends on how the original financial institution sells the mortgage to new institutions. Generally the homeowner would keep paying initial financial institution and they would then take a margin and pay the secondary investor. If this was collateral-ized as Mortgage backed security, it is a very different story." You better buy an ETF that does the same, because it would be much cheaper than mutual fund (and probably much cheaper than doing it yourself and rebalancing to keep up with the index).  Look at DIA for example. Neither buying the same amount of stocks nor buying for the same amount of money would be tracking the DJIE. The proportions are based on the market valuation of each of the companies in the index. "You don't need to use a real stock like GLD.  You can just create a ""stock"" called something like ""1 oz Gold"" and buy and sell them as if they were shares.  It won't auto-update the price like GLD, but that's not a big deal to update manually once a month or so. I prefer to have accurate data that is correct at a particular point in time to having data that is 2-3% off, or that requires entering the ounces as 10x reality.  YMMV. This is very similar to how you track US Savings Bonds in Quicken (and might be described in the help under that topic.)" the strategy is tested all the way to 97. how is the continuous series backadjusted? the emini is rolledover and Ratio back adjusted to the 2nd nearest contract, 9 days prior to expiration. since it is an intraday trade, the discrepancy to the real thing should be next to irrelevant. but comparing it to the spx could make it interesting.  what would be a good format to present the results ? jpeg? pdf ?