What kind of trade is this?
A limit order is simply an order to buy at a maximum price or sell at a minimum price. For example, if the price is $100 and you want to sell if the price rises to $110, then you can simply put a limit order to sell at $110. The order will be placed in the market and when the price reaches $110 your order will be executed. If the price gaps at the open to $111, then you would end up selling for $111. In other words you will get a minimum of $110 per share. A stop limit order is where you put a stop loss order, which when it gets triggered, will place a limit order in the market for you. For example, you want to limit your losses by placing a stop loss order if the price drops to $90. If you chose a market order with your stop loss as soon as the price hits $90 your stop loss would be triggered and the shares would sell at the next available price, usually at $90, but could be less if the market gaps down past $90. If on the other hand you placed a limit order at $89.50 with your stop loss, when the stop loss order gets triggered at $90 your limit order will be placed into the market to sell at $89.50. So you would get a minimum of $89.50 per share, however, if the market gaps down below $89.50 your order will be placed onto the market but it won't sell, unless the price goes back to or above $89.50. Hope this helps. "The question mentions a trailing stop. A trailing stop is a type of stop loss order. It allows you to protect your profit on the stock, while ""keeping you in the stock"". A trailing stop is specified as a percentage of market price e.g. you might want to set a trailing stop at 5%, or 10% below the market price. A trailing stop goes up along with the market price, but if the market price drops it doesn't move down too. The idea is that it is there to ""catch"" your profit, if the market suddenly moves quickly against you. There is a nice explanation of how that works in the section titled Trailing Stops here. (The URL for the page, ""Tailing Stops"" is misleading, and a typo, I suspect.)"
"In 2014 the IRS announced that it published guidance in Notice 2014-21. In that notice, the answer to the first question describes the general tax treatment of virtual currency: For federal tax purposes, virtual currency is treated as property. General tax principles applicable to property transactions apply to transactions using virtual currency. As it's property like any other, capital gains if and when you sell are taxed. As with any capital gains, you're taxed on the ""profit"" you made, that is the ""proceeds"" (how much you got when you sold) minus your ""basis"" (how much you paid to get the property that you sold). Until you sell, it's just an asset (like a house, or a share of stock, or a rare collectible card) that doesn't require any reporting. If your initial cryptocurrency acquisition was through mining, then this section of that Notice applies: Q-8: Does a taxpayer who “mines” virtual currency (for example, uses computer resources to validate Bitcoin transactions and maintain the public Bitcoin transaction ledger) realize gross income upon receipt of the virtual currency resulting from those activities? A-8: Yes, when a taxpayer successfully “mines” virtual currency, the fair market value of the virtual currency as of the date of receipt is includible in gross income. See Publication 525, Taxable and Nontaxable Income, for more information on taxable income. That is to say, when it was mined the market value of the amount generated should have been included in income (probably on either Line 21 Other Income, or on Schedule C if it's from your own business). At that point, the market value would also qualify as your basis. Though I doubt there'd be a whole lot of enforcement action for not amending your 2011 return to include $0.75. (Technically if you find a dollar bill on the street it should be included in income, but usually the government cares about bigger fish than that.) It sounds like your basis is close enough to zero that it's not worth trying to calculate a more accurate value. Since your basis couldn't be less than zero, there's no way that using zero as your basis would cause you to pay less tax than you ought, so the government won't have any objections to it.  One thing to be careful of is to document that your holdings qualify for long-term capital gains treatment (held longer than a year) if applicable. Also, as you're trading in multiple cryptocurrencies, each transaction may count as a ""sale"" of one kind followed by a ""purchase"" of the other kind, much like if you traded your Apple stock for Google stock. It's possible that ""1031 like kind exchange"" rules apply, and in June 2016 the American Institute of CPAs sent a letter asking about it (among other things), but as far as I know there's been no official IRS guidance on the matter. There are also some related questions here; see ""Do altcoin trades count as like-kind exchanges?"" and ""Assuming 1031 Doesn't Apply To Cryptocurrency Trading"". But if in fact those exchange rules do not apply and it is just considered a sale followed by a purchase, then you would need to report each exchange as a sale with that asset's basis (probably $0 for the initial one), and proceeds of the fair market value at the time, and then that same value would be the basis of the new asset you're purchasing. Using a $0 basis is how I treat my bitcoin sales, though I haven't dealt with other cryptocurrencies. As long as all the USD income is being reported when you get USD, I find it unlikely you'll run into a lot of trouble, even if you technically were supposed to report the individual transactions when they happened. Though, I'm not in charge of IRS enforcement, and I'm not aware of any high-profile cases, so it's hard to know anything for sure. Obviously, if there's a lot of money involved, you may want to involve a professional rather than random strangers on the Internet. You could also try contacting the IRS directly, as believe-it-or-not, their job is in fact helping you to comply with the tax laws correctly. Also, there are phone numbers at the end of Notice 2014-21 of people which might be able to provide further guidance, including this statement: The principal author of this notice is Keith A. Aqui of the Office of Associate Chief Counsel (Income Tax & Accounting). For further information about income tax issues addressed in this notice, please contact Mr. Aqui at (202) 317-4718" "- In a quote driven market, must every investor trade with a market        maker? In other words, two parties that are both not market makers        cannot trade between themselves directly? In a way yes, all trades go through a market maker but those trades can be orders put in place by a ""person"" IE: you, or me. - Does a quote driven market only display the ""best"" bid and ask        prices proposed by the market makers? In other words, only the        highest bid price among all the market makers is displayed, and        other lower bid prices by other market makers are not? Similarly,        only the lowest ask price over all market makers is displayed, and        other higher ask prices by other market makers are not? No, you can see other lower bid and higher ask prices. - In a order-driven market, is it meaningful to talk about ""the current stock price"", which is the price of last transaction? Well that's kind of an opinion. Information is information so it won't be bad to know it. Personally I would say the bid and ask price is more important. However in the real world these prices are changing constantly and quickly so realistically it is easier to keep track of the quote price and most likely the bid/ask spread is small and the quote will fall in between. The less liquid a security is the more important the bid/ask is. -- This goes for all market types. - For a specific asset, will there be several transactions happened at    the same time but with different prices? Today with electronic markets, trades can happen so quickly it's difficult to say. In the US stock market trades happen one at a time but there is no set time limit between each trade. So within 1 second you can have a trade be $50 or $50.04. However it will only go to $50.04 when the lower ask prices have been exhausted.   - Does an order driven market have market makers?  By definition, no. - What are some examples of quote driven and order driven financial markets, in which investors are commonly trading stocks and derivatives, especially in U.S.? Quote driven market: Bond market, Forex. Order driven market: NYSE comes from an order driven market but now would be better classified as a ""hybird market"" Conclusion: If you are asking in order to better understand today's stock markets then these old definitions of Quote market or Order market may not work. The big markets in the real world are neither. (IE: Nasdaq, NYSE...) The NYSE and Nasdaq are better classified as a ""hybird market"" as they use more then a single tactic from both market types to insure market liquidity, and transparency. Markets these days are strongly electronic, fast, and fairly liquid in most cases. Here are some resources to better understand these markets: An Introduction To Securities Markets The NYSE And Nasdaq: How They Work Understanding Order Execution" This depends on a combination of factors: What are you charged (call it margin interest) to hold the position? How does this reduce your buying power and what are the opportunity costs? What are the transaction costs alternative ways to close the position? What are your risks (exposure while legging out) for alternative ways to close? Finally, where is the asset closing relative to the strike? Generally, If asset price is below the put strike then the call expires worthless and you need to exercise the put. If asset is above the call strike then put expires worthless and you'll likely get assigned.  Given this framework:  If margin interest is eating up your profit faster than you're earning theta (a convenient way to represent the time value) then you have some urgency and you need to exit that position before expiry. I would not exit the stock until the call is covered. Keep minimal risk at all times. If you are limited by the position's impact on your buying power and probable value of available opportunities is greater than the time decay you're earning then once again, you have some urgency about closing instead of unwinding at expiry. Same as above. Cover that call, before you ditch your hedge in the long stock. Playing the tradeoff game of expiration/exercise cost against open market transactions is tough. You need sub-penny commissions on stock (and I would say a lot of leverage) and most importantly you need options charges much lower than IB to make that kind of trading work. IB is the cheapest in the retail brokerage game, but those commissions aren't even close to what the traders are getting who are more than likely on the other side of your options trades. In terms of building the initial investment using some kind of mutual fund, I'd suggest you see my answer to this similar question https://money.stackexchange.com/questions/9943/cheapest-or-free-online-broker-for-beginner For buying individual stocks later, you could look at sharebuilder, or a low cost broker, however most of them charge between $5-$7 per trade, and if you are doing small dollar value trades then that can really really eat into things if you try to trade a lot. I'd probably call it an intangible or indirect benefit. Not sure what the trade term is. "I can address what it means to ""pick off"" all those trades... As quantycuenta & littleadv have said, it is absolutely true that professionals ""prey"" on less-sophisticated market participants. They aren't in the market for charity's sake.  If you're not familiar with the definition of the word ""arbitrage"", look it up.  One possible strategy that can be employed with HFT machinery in order to arbitrage successfully in the stock market is to 'intercept' orders that are placed on various exchanges. In order to do this, an HFT organization watches all the transactions at once to find opportunities to buy low and sell high.  A good explanation of it is described here in this NY Times article; I'll paraphrase what that article lays out.  Stocks are traded through multiple exchanges The first key point to understand is that stocks listed on one exchange (i.e. the NYSE) can be sold on multiple exchanges. That's where the actual ""I would like to sell 100 shares of Ford stock"" is matched with ""I would like to buy 100 shares of Ford stock."" There are multiple clearinghouses on the various exchanges. Your order gets presented to one exchange at a Time An ideal market maker would like to look at the order books for a given stock, say Ford, and see that in exchange A there's a sell order for 100 shares of F at $15.85, and in exchange B there's a buy order for 100 shares of F at $15.90.  Arbitrage Market maker buys from A, sells in B, and pockets $0.05 * 100... $5. It's not much, but it was relatively risk free. Also, scale this up to the scale of the US' multiple stock exchanges, and there are lots of opportunities to make $5 every second.  Computers are (of course) faster than people To tie it in completely with your question about 'picking off trades', HFT rigs can be set up and programmed to go faster than an average retail investor's order.  Let's say you execute the trade to buy 100 shares @ $15.85 as a retail investor. The HFT rigs see your order starting to make the rounds of the different exchanges that your brokerage works through, and go out in front in a matter of milliseconds, finding the orders that are less than $15.85 and less than or equal to 100 shares. They execute a transaction, buy them up, sell to you, and pocket the difference.  You have been ""picked off"".  It's admittedly not the only way to use HFT equipment to make money, but it's definitely one way to do it." I just finished a high frequency trading project. Individuals can do it, but you need a lot of capital. You can get a managed server in Times Square for $1500/month, giving you access to 90% of the US exchanges that matter, their data farms are within 3 milliseconds of distance (latency). You can also get more servers in the same building as the exchanges, if you know where to look ;) thats all I can divulge good luck They could have different quotes as there are more than a few pieces here.  Are you talking a Real Time Level II quote or just a delayed quote?  Delayed quotes could vary as different companies would be using different time points in their data.  You aren't specifying exactly what kind of quote from which system are you using here. The key to this question is how much of a pinpoint answer do you want and how prepared are you to pay for that kind of access to the automated trades happening?  Remember that there could well be more than a few trades happening each millisecond and thus latency is something to be very careful here, regardless of the exchange as long as we are talking about first-world stock exchanges where there are various automated systems being used for trading. Different market makers is just a possible piece of the equation here.  One could have the same market maker but if the timings are different,e.g. if one quote is at 2:30:30 and the other is at 2:30:29 there could be a difference given all the trades processed within that second, thus the question is how well can you get that split second total view of bids and asks for a stock.  You want to get all the outstanding orders which could be a non-trivial task.