How does my broker (optionsXpress) calculate probabilities that the stock will hit a certain price?
"This chart concerns an option contract, not a stock. The method of analysis is to assume that the price of an option contract is normally distributed around some mean which is presumably the current price of the underlying asset. As the date of expiration of the contract gets closer the variation around the mean in the possible end price for the contract will decrease. Undoubtedly the publisher has measured typical deviations from the mean as a function of time until expiration from historical data. Based on this data, the program that computes the probability has the following inputs: (1) the mean (current asset price) (2) the time until expiration (3) the expected standard deviation based on (2) With this information the probability distribution that you see is generated (the green hump). This is a ""normal"" or Gaussian distribution. For a normal distribution the probability of a particular event is equal to the area under the curve to the right of the value line (in the example above the value chosen is 122.49). This area can be computed with the formula:  This formula is called the probability density for x, where x is the value (122.49 in the example above). Tau (T) is the reciprocal of the variance (which can be computed from the standard deviation). Mu (μ) is the mean. The main assumption such a calculation makes is that the price of the asset will not change between now and the time of expiration. Obviously that is not true in most cases because the prices of stocks and bonds constantly fluctuate. A secondary assumption is that the distribution of the option price around the mean will a normal (or Gaussian) distribution. This is obviously a crude assumption and common sense would suggest it is not the most accurate distribution. In fact, various studies have shown that the Burr Distribution is actually a more accurate model for the distribution of option contract prices." "Their algorithm may be different (and proprietary), but how I would to it is to assume that daily changes in the stock are distributed normally (meaning the probability distribution is a ""bell curve"" - the green area in your chart).  I would then calculate the average and standard deviation (volatility) of historical returns to determine the center and width of the bell curve (calibrating it to expected returns and implied volaility based on option prices), then use standard formulas for lognormal distributions to calculate the probability of the price exceeding the strike price. So there are many assumptions involved, and in the end it's just a probability, so there's no way to know if it's right or wrong - either the stock will cross the strike or it won't."
"Being ""Long"" something means you own it.  Being ""Short"" something means you have created an obligation that you have sold to someone else.  If I am long 100 shares of MSFT, that means that I possess 100 shares of MSFT.  If I am short 100 shares of MSFT, that means that my broker let me borrow 100 shares of MSFT, and I chose to sell them.  While I am short 100 shares of MSFT, I owe 100 shares of MSFT to my broker whenever he demands them back.  Until he demands them back, I owe interest on the value of those 100 shares.  You short a stock when you feel it is about to drop in price.  The idea there is that if MSFT is at $50 and I short it, I borrow 100 shares from my broker and sell for $5000.  If MSFT falls to $48 the next day, I buy back the 100 shares and give them back to my broker.  I pocket the difference ($50 - $48 = $2/share x 100 shares = $200), minus interest owed.  Call and Put options.  People manage the risk of owning a stock or speculate on the future move of a stock by buying and selling calls and puts.  Call and Put options have 3 important components.  The stock symbol they are actionable against (MSFT in this case), the ""strike price"" - $52 in this case, and an expiration, June.  If you buy a MSFT June $52 Call, you are buying the right to purchase MSFT stock before June options expiration (3rd Saturday of the month).  They are priced per share (let's say this one cost $0.10/share), and sold in 100 share blocks called a ""contract"".  If you buy 1 MSFT June $52 call in this scenario, it would cost you 100 shares x $0.10/share = $10.  If you own this call and the stock spikes to $56 before June, you may exercise your right to purchase this stock (for $52), then immediately sell the stock (at the current price of $56) for a profit of $4 / share ($400 in this case), minus commissions.  This is an overly simplified view of this transaction, as this rarely happens, but I have explained it so you understand the value of the option.  Typically the exercise of the option is not used, but the option is sold to another party for an equivalent value.  You can also sell a Call.  Let's say you own 100 shares of MSFT and you would like to make an extra $0.10 a share because you DON'T think the stock price will be up to $52/share by the end of June.  So you go to your online brokerage and sell one contract, and receive the $0.10 premium per share, being $10.  If the end of June comes and nobody exercises the option you sold, you get to keep the $10 as pure profit (minus commission)!  If they do exercise their option, your broker makes you sell your 100 shares of MSFT to that party for the $52 price.  If the stock shot up to $56, you don't get to gain from that price move, as you have already committed to selling it to somebody at the $52 price.  Again, this exercise scenario is overly simplified, but you should understand the process.  A Put is the opposite of a Call.  If you own 100 shares of MSFT, and you fear a fall in price, you may buy a PUT with a strike price at your threshold of pain.  You might buy a $48 June MSFT Put because you fear the stock falling before June.  If the stock does fall below the $48, you are guaranteed that somebody will buy yours at $48, limiting your loss.  You will have paid a premium for this right (maybe $0.52/share for example).  If the stock never gets down to $48 at the end of June, your option to sell is then worthless, as who would sell their stock at $48 when the market will pay you more?  Owning a Put can be treated like owning insurance on the stock from a loss in stock price.  Alternatively, if you think there is no way possible it will get down to $48 before the end of June, you may SELL a $48 MSFT June Put.  HOWEVER, if the stock does dip down below $48, somebody will exercise their option and force you to buy their stock for $48.  Imagine a scenario that MSFT drops to $30 on some drastically terrible news.  While everybody else may buy the stock at $30, you are obligated to buy shares for $48.  Not good!  When you sold the option, somebody paid you a premium for buying that right from you.  Often times you will always keep this premium.  Sometimes though, you will have to buy a stock at a steep price compared to market.  Now options strategies are combinations of buying and selling calls and puts on the same stock.  Example -- I could buy a $52 MSFT June Call, and sell a $55 MSFT June Call.  I would pay money for the $52 Call that I am long, and receive money for the $55 Call that I am short.  The money I receive from the short $55 Call helps offset the cost of buying the $52 Call.  If the stock were to go up, I would enjoy the profit within in $52-$55 range, essentially, maxing out my profit at $3/share - what the long/short call spread cost me.  There are dozens of strategies of mixing and matching long and short calls and puts depending on what you expect the stock to do, and what you want to profit or protect yourself from.  A derivative is any financial device that is derived from some other factor.  Options are one of the most simple types of derivatives.  The value of the option is derived from the real stock price.  Bingo?  That's a derivative.  Lotto?  That is also a derivative.  Power companies buy weather derivatives to hedge their energy requirements.  There are people selling derivatives based on the number of sunny days in Omaha.  Remember those calls and puts on stock prices?  There are people that sell calls and puts based on the number of sunny days in Omaha.  Sounds kind of ridiculous -- but now imagine that you are a solar power company that gets ""free"" electricity from the sun and they sell that to their customers.  On cloudy days, the solar power company is still on the hook to provide energy to their customers, but they must buy it from a more expensive source.  If they own the ""Sunny Days in Omaha"" derivative, they can make money for every cloudy day over the annual average, thus, hedging their obligation for providing more expensive electricity on cloudy days.  For that derivative to work, somebody in the derivative market puts a price on what he believes the odds are of too many cloudy days happening, and somebody who wants to protect his interests from an over abundance of cloudy days purchases this derivative.  The energy company buying this derivative has a known cost for the cost of the derivative and works this into their business model.  Knowing that they will be compensated for any excessive cloudy days allows them to stabilize their pricing and reduce their risk.  The person selling the derivative profits if the number of sunny days is higher than average.  The people selling these types of derivatives study the weather in order to make their offers appropriately.  This particular example is a fictitious one (I don't believe there is a derivative called ""Sunny days in Omaha""), but the concept is real, and the derivatives are based on anything from sunny days, to BLS unemployment statistics, to the apartment vacancy rate of NYC, to the cost of a gallon of milk in Maine.  For every situation, somebody is looking to protect themselves from something, and somebody else believes they can profit from it.  Now these examples are highly simplified, many derivatives are highly technical, comprised of multiple indicators as a part of its risk profile, and extremely difficult to explain.  These things might sound ridiculous, but if you ran a lemonade stand in Omaha, that sunny days derivative just might be your best friend..." Your understanding of the stock market is absolutely correct theoretically. However there is a lot more to it. A stock on a given day is effected by a lot of factors. These factors could really be anything. For example, if you are buying a stock in an agricultural company and there was no rainfall this year, there is a big chance that your stock will lose value. There is also a chance that a war breaks out tomorrow and due to all the government spending on the war, the economy collapses and effects the prices of stocks. Why does this happen? This happens because bad rainfall or war can get people to lose confidence in a stock market. On the other hand GDP growth and low unemployment rates can make people think positive and increase the demand in a stock driving the prices up. The main factor in the stock market is sentiment(How people perceive certain news). This causes a stock to rise or fall even before the event actually happens. (For example:- Weather pundits predicted good rainfall for next year. That news is already known to people, so if the weather pundit was correct, it might not drive the prices up. However, if the rainfall was way better than people expected it to be it would drive the price up and vice versa.   These are just examples at a basic level. There are a lot of other factors which determine the price of the stock. The best way to look at it(In my personal opinion) is the way Warren Buffet puts it, i.e. look at the stock as a business and see the potential growth over a long period of time.  There will be unexpected events, but in the long run, the business must be profitable. There are various ways to value a company such as Price to earnings ratios, PEG ratios, discounted cash flows and you can also create your own. See what works best for you and record your success/failure ratio before you actually put money in.  Good Luck, "First, let me say that $1000 is not that much of amount to invest in stocks. You need to remember that each transaction (buy/sell) has fees, which vary between $4-$40 (depending on the broker, you mentioned Scottrade - they charge $7 per transaction for stocks and about twice as much for some mutual funds). Consider this: you invest $1000, you gain $100. You'll pay $15 in fees just to buy/sell, that's 1.5% expense ratio. If you invest in more than 1 stock - multiply your fees. To avoid that you can look into mutual funds. Different brokers offer different funds for free, and almost all of them carry many of the rest for a fee. When looking into funds, you can find their expense ratio and compare. Remember that a fund with 1% expense ratio diversifies and invests in many stocks, while for you 1.5% expense ratio is for investing in a single stock. Is it a good idea to invest only in US or diversify worldwide? You can invest in the US, but in funds that diversify worldwide or across industries. Generally it is a good idea to diversify. I am 28. Should I be a conservative investor or take some risks? Depends on how bad of a shape will you be if you lose all your principle. What online brokerage service is the best? I have heard a lot about   Scotttrade but want to be sure before I start. It seems to be the   least expensive and most user-friendly to me. ""Best"" is a problematic term. Scottrade is OK, E*Trade is OK, you can try Sharebuilder, Ameritrade, there are several ""discount"" online brokers and plenty of on-line reviews and comparisons amongst them. What is a margin account and how would it affect my investing? From   what I understand it comes into play when an investor borrows money   from the broker. Do I need to use it at all as I won't be investing on a big scale yet. You understand right. There are rules to use margin accounts, and with the amount you have I'd advise against them even if you get approved. Read through the brokers' FAQ's on their requirement. Should I keep adding money on a monthly basis to my brokerage account   to give me more money to invest or keep it at a certain amount for an   extended period of time? Sharebuilder has a mechanism to purchase monthly at discounted prices. But be careful, they give you discounted prices to buy, but not to sell. You may end up with a lot of positions, and the discounts you've gotten to buy will cause you spend much more on selling. Generally, averaging (investing monthly) is a good way to save and mitigate some risks, but the risks are still there. This is good only for long term savings. How should my breakdown my investments in terms of bonds vs stocks? Depends on your vulnerability and risk thresholds." Here's the purely mathematical answer for which fees hurt more. You say taking the money out has an immediate cost of $60,000. We need to calculate the present value of the future fees and compare it against that number. Let's assume that the investment will grow at the same rate either with or without the broker. That's actually a bit generous to the broker, since they're probably investing it in funds that in turn charge unjustifiable fees. We can calculate the present cost of the fees by calculating the difference between: As it turns out, this number doesn't depend on how much we should expect to get as investment returns. Doing the math, the fees cost: 220000 - 220000 * (1-0.015)^40 = $99809 That is, the cost of the fees is comparable to paying nearly $100,000 right now. Nearly half the investment! If there are no other options, I strongly recommend taking the one-time hit and investing elsewhere, preferably in low-cost index funds. Details of the derivation. For simplicity, assume that both fees and growth compound continuously. (The growth does compound continuously. We don't know about the fees, but in any case the distinction isn't very significant.) Fees occur at a (continuous) rate of rf = ln((1-0.015)^4) (which is negative), and growth occurs at rate rg. The OPs current principal is P, and the present value of the fees over time is F. We therefore have the equation P e^((rg+rf)t) = (P-F) e^(rg t) Solving for F, we notice that the e^rg*t components cancel, and we obtain F = P - P e^(rf t) = P - P e^(ln((1-0.015)^4) t) = P - P (1-0.015)^(4t) But how does the quantity matching happen? For example, if I want to buy 1000 shares at $100, but there is only one seller to sell 10 shares at $100, what happens then? This depends on the type of order you've placed. If you placed a fill-or-kill order, your order to buy or sell a certain number of shares is routed to the trading floor for immediate execution. If the order cannot be immediately filled, it is cancelled (killed) automatically. Note that the order must be filled in its entirety. Partial fills are not allowed. In your example, your buy order wouldn't be filled because it couldn't be matched to a sell order of the same volume. This is similar to an all-or-none order, which is an order that contains  A condition instructing the broker to fill the order completely or not at all. If there is insufficient supply to meet the quantity requested by the order then it is canceled at the close of the market. In this case, if your order wasn't matched to an order of the same volume by the time the market closes, it's cancelled. If you simply placed a market/limit order, and (in the case of the limit order), part of your order was matched to another order with the right price, that part of your order will be filled, while the rest will remained unfilled. Focusing on options, many people and companies use them to mitigate risk(hedge)  When used as a hedge the objective is not to win big, it is to create a more predictable outcome. Option traders win big by consistenly structuring trades with a high probability of success. In this way, they take 100 and turn it into 1000 with 100 small trades with a target profit of $10/trade.  Although options are a 'zero sum' game, a general theory among options traders is the stock market only has a 54-56 probability of profit(PoP) - skewed from 50-50 win/loss because the market tends to go up over a long time frame. Using Option trading strategies strategically, you have more control over PoP and you can set yourself up to win whether the security goes up/down/sideways.   A quick and dirty measure of PoP is an options' delta.  If the delta on a call option is 19, there is roughly a 19% chance your option will be in the money at expiration - or a 19% chance of hitting a home run and multiplyimg your money.  If the delta is 68, there is a 68% chance of a profitable trade or getting on base. There are more variables to this equation, but  I hope this clearly explains the essence. "To understand the VXX ETF, you need to understand VIX futures, to understand VIX futures you need to understand VIX, to understand VIX you need to understand options pricing formulas such as the ""Black Scholes"" formula Those are your prerequisites. Learn at your own pace. Short Answer: When you buy VXX you are buying the underlying are front month VIX futures. Limited by the supply of the ETF's NAV (Net Asset Value) units. It is assumed that the ETF manager is actually buying and selling more VIX front month futures to back the underlying ETF. Long Answer: Assume nobody knows what an options contract should be worth. Therefore formulas have been devised to standardize how to price an options contract. The Black-Scholes formula is widely used, one of the variables in this formula is ""Implied Volatility"", which basically accounts for the mispricing of options when the other variables (Intrinsic Value, delta, gamma, theta...) don't completely explain how much the option is worth. People are willing to pay more for options when the perception is that they will be more profitable, ""implied volatility"" tracks these changes in an option's demand, where the rest of the black-scholes formula creates a price for an option that will always be the same. Each stock in the market that also trades standardized options will have implied volatility which can be computed from the price of those options. The ""Volatility Index"" (VIX), looks at the implied volatility of MANY STOCK's options contracts. Specifically the ""implied volatility of out the money puts on the S&P 500"". If you don't know what that quoted part of the sentence means, then you have at least five other individual questions to ask before you re-read this answer and understand the relevance of these followup questions: Why would people buy out-the-money puts on the S&P 500? Why would people pay more for out-the-money puts on the S&P 500 on some days and pay less for them on other days? This is really the key to the whole puzzle. Anyway, now that we have this data, people wanted to speculate on the future value of the VIX. So VIX futures contracts began trading and with it there came a liquid market. There doesn't need to be anything physical to back a financial product anymore. A lot of people don't trade futures, retail investors have practically only heard of ""the stock market"". So one investment bank decided to make a fund that only holds VIX futures that expire within a month. (front month futures). They split that fund up into shares and listed it on the stock market, like alchemy the VXX was formed. Volatility studies are fascinating, and get way more complex than this now that the VXX ETF also has liquid options contracts trading on it too, and there are leveraged VIX ETF funds that also trade options" In the equity world, if a stock trades at 110 and is going to pay a dividend of 10 in a few days, an option expiring after the ex date would take the dividend into account and would trade as if the stock were trading at 100. (Negative) interest rates may also lead to a similar effect. In the commodity world the cost of carry needs to be taken into account.