Why are stop order called “stop” when it is in fact a “start” condition?
A stop order can be used to both enter or exit a position. A stop loss is used to set the price you want to get out if the price reaches that level. Whilst a stop buy or entry order is used to get into a position if the price reaches your desired level for entry. The stop order just means that you want to place your order at that level, you then need to specify if you are buying to open, selling to open, buying to close or selling to close your position at the stop level. "Historically they were conceived as a way to cut losses when the market turned against you. You would tell your broker something like ""buy me 100 shares of Anaconda and stop me if it goes below $110"" You can read references to this in old books like Reminiscences of a Stock Operator, the ABC of Options pricing, or the Day Trader's Bible."
When you place a bid between the bid/ask spread, that means you are raising the bid (or lowering the ask, if you are selling). The NBBO (national best bid and offer) is now changed because of your action, and yes, certain kinds of orders may be set to react to that (a higher bid or lower ask triggering them), also many algorithms (that haven't already queued an order simply waiting for a trigger, like in a stop limit) read the bid and ask and are programmed to then place an order at that point. There is a technique called the Elliott wave which explains these 'shocks'. The reversal directions you are questioning are part of the pattern, it is known as corrections. The Elliott wave is an indicator based on psychology of investors. Think about it this way, if you see a huge up trend what are you most likely to do, sell and make profit or continue, this is why there is a shock before it continues. Many people will sell to be safe, especially after hearing the bad news they won't risk it. By learning the Elliott wave you'll be able to make an educated decision on whether or not to stay or leave. Here are websites on the Elliott wave: http://stockcharts.com/school/doku.php?id=chart_school:market_analysis:elliott_wave_theory http://www.swing-trade-stocks.com/elliott-wave.html The Elliott wave is helpful in any time frame and works well with momentum. Hope this helps. A stop-loss order becomes a market order when a trade has occurred at or below the trigger price you set when creating the order. This means that you could possibly end up selling some or all of your position at a price lower than your trigger price. For relatively illiquid securities your order may be split into transactions with several buyers at different prices and you could see a significant drop in price between the first part of the order and the last few shares. To mitigate this, brokers also offer a stop-limit order, where you set not only a trigger price, but also a minimum price that you are will to accept for your shares. This reduces the risk of selling at rock bottom prices, especially if you are selling a very large position. However, in the case of a flash crash where other sellers are driving the price below your limit, that part of your order may never execute and you could end up being stuck with a whole lot of shares that are worth less than both your stop loss trigger and limit price. For securities that are liquid and not very volatile, either option is a pretty safe way to cut your losses. For securities that are illiquid and/or very volatile a stop-limit order will prevent you from cashing out at bottom dollar and giving away a bargain to lurkers hanging out at the bottom of the market, but you may end up stuck with shares you don't want for longer than originally planned. It's up to you to decide which kind of risk you prefer. "Not sure why CAGR is a problem for both directions. I used to be a physicist, and, when I taught classes in graduate school, students always wanted to use the terms ""accelerate"" and ""decelerate"" to describe ""speeding up"" and ""slowing down"". But acceleration is just a vector with magnitude and direction. There's nothing special about slowing down that it needs a special name. It's just acceleration in a direction opposite to the direction of motion. I think the same thing applies here. There's nothing special about negative growth rates that they need a special name. Just stick a minus sign in front of the number and you convey the required information." Because in the case for 100/101, if you wanted to placed a limit buy order at top of the bid list you would place it at 101 and get filled straight away. If placing a limit buy order at the top of 91 (for 90/98) you would not get filled but just be placed at the top of the list. You might get filled at a lower price if an ask comes in matching your bid, however you might never get filled. In regards to market orders, with the 100/101 being more liquid, if your market order is larger than the orders at 101, then the remainder of your order should still get filled at only a slightly higher price. In regards to market orders with the 90/98, being less liquid, it is likely that only part of your order gets filled, and any remained either doesn't get filled or gets filled at a much higher price. The purpose of a market order is to guarantee that your order gets filled. If you try to place a limit order at the bid or ask, by the time you enter your order the price might have moved and you might need to keep amending your limit order in order to buy or sell, and as such you start chasing the market. A market order will guarantee your order gets executed. Also, an important point to consider, is that market orders are often used in combination with other orders such as conditional orders. For example if you have a stop loss (conditional order) set at say 10% below your buy price, you might want to use a market order to make sure your order gets executed if the price drops 10% and your stop loss gets triggered, making sure that you get out of the stock instead of being stuck with a limit order 10% below your buy price whilst the stock keeps falling further. The volume required to significantly move the price of a security depends completely on the orderbook for that particular security. There are a variety of different reasons and time periods that a security can be halted, this will depend a bit on which exchange you're dealing with. This link might help with the halt aspect of your question: https://en.wikipedia.org/wiki/Trading_halt During a circuit breaker, no trading occurs. These policies have been implemented to maintain exchange liquidity since the NYSE nearly went bankrupt during the 1987 crash because many members had become insolvent. If an order is filled before the halt, it will stand unless busted.  During the Flash Crash, many orders were busted. Capping the upside while playing with unlimited downside is a less disciplined investment strategy vis-a-vis a stop-loss driven strategy. Whether it is less risky or high risky also depends on the fluctuations of the stock and not just long-term movements. For example, your stop losses might get triggered because of a momentary sharp decline in stock price due to a large volume transaction (esp more so in small-cap stocks). Although, the stock price might recover from the sudden price drop pretty soon causing a seemingly preventable loss. That being said, playing with stop losses is always considered a safer strategy. It may not increase your profits but can certainly cap your losses. "I found the answer after some searching online. It turns out that when talking options, rarely is the current P/L line considered when talking about making adjustments/taking trades off. From Investopedia: http://www.investopedia.com/terms/b/breakevenpoint.asp ""... For options trading, the breakeven point is the market price that a stock must reach for an option buyer to avoid a loss if they exercise the option. For a call buyer, the breakeven point is the strike price plus the premium paid, while breakeven for a put position is the strike price minus the premium paid."" The first sentence sounds more like the current P/L line, but the bold section clearly states the rule I was looking for. In the example posted in my question above, the breakpoints labeled with ""1"" would be the break points I should consider." "The emphasis of ""stop loss"" is ""stop"", not ""loss"". Stop and long term are contradictory. After you stop, what are you going to do with your cash? Since it's long term, you still have 5+ years to before you use the money, do you simply park everything in 0.5% savings account? On the other hand, if your investment holds N stocks and one has dropped a lot, you are free to switch to another one. This is just an investment strategy and you are still in the market." The company may have put a trading halt due to many reasons, most of the time it is because the company is about to release some news to the market. To stop speculation driving the price up or down, it puts a halt on trading until it can get all the information together and release it to the market. This could be news about an earnings update, a purchase of other businesses, a merger with another business, or a takeover bid, just to name a few. "Your logic breaks down because you assume that you are the only market participant on your side of the book and that the participant on the other side of the book has entered a market order. Here's what mostly happens: Large banks and brokerages trading with their own money (we call it proprietary or ""prop"" trading) will have a number of limit (and other, more exotic) orders sitting on both sides of the trading book waiting to buy or sell at a price that they feel is advantageous. Some of these orders will have sat on the book for many months if not years. These alone are likely to prevent your limit orders executing as they are older so will be hit first even if they aren't at a better price.  On more liquid stocks there will also be a number of participants entering market orders on both sides of the book whose orders are matched up before limit orders are matched with any market orders. This means that pairing of market orders, at a better price, will prevent your limit order executing. In many markets high frequency traders looking for arbitrage opportunities (for example) will enter a few thousand orders a minute, some of these will be limit orders just off touch, others will be market orders to be immediately executed. The likelihood that your limit order, being as it is posited way off touch, is hit with all those traders about is minimal. On less liquid stocks there are market makers (large institutional traders) who effectively set the bid and offer prices by being willing to provide liquidity and fill the market orders at a temporary loss to themselves and will, in most cases, have limit orders set to provide this liquidity that will be close to touch. They are paid to do this by the exchange and inter-dealer brokers through their fees structure. They will fill the market orders that would hit your limit if they think that it would provide more liquidity in such a way that it fulfils their obligations. Only if there are no other participants looking to trade on the instrument at a better price than your limit (which, of course they can see unless you enter it into a dark pool) AND there is a market order on the opposite side of the book will your limit order be instantaneously be hit, executed, and move the market price." The situation you're proposing is an over-simplification that wouldn't occur in practice. Orders occur in a sequence over time. Time is an important part of the order matching process. Orders are not processed in parallel; otherwise, the problem of fairness, already heavily regulated, would become even more complex. First, crossed and locked markets are forbidden by regulators.  Crossed orders are where one exchange has a higher bid than another's ask, or a lower ask than another's bid.  A locked market is where a bid on one exchange is equal to the ask on another.  HFTs would be able to make these markets because of the gap between exchange fees. Since these are forbidden, and handling orders in parallel would ensure that a crossed or locked market would occur, orders are serialized (queued up), processed in order of price-time priority. So, the first to cross the market will be filled with the best oldest opposing order. Regulators believe crossed or locked markets are unfair.  They would however eliminate the bid ask spread for many large securities thus the bid-ask cost to the holder. "Market orders do not get priority over limit orders.  Time is the only factor that matters in price/time order matching when the order price is the same. For example, suppose the current best available offer for AAPL is $100.01 and the best available bid is $100.00.  Now a limit buy for $100.01 and a market buy arrive at around the same instant.  The matching engine can only receive one order at a time, no matter how close together they arrive. Let's say that by chance the limit buy arrives first.  The engine will check if there's a matching sell at $100.01 and indeed there is and a trade occurs.  This all happens in an instant before the matching engine ever sees the market buy.  Then it moves on to the market buy and processes it accordingly. On the other hand, let's say that by chance the market buy arrives first.  The engine will match it with the best available sell (at $100.01) and a trade occurs.  This all happens in an instant before the matching engine ever sees the limit buy.  Then it moves on to the limit buy and processes it accordingly. So there's never a comparison between the two orders or their ""priorities"" because they never exist in the system at the same time.  The first one to arrive is processed first; the second one to arrive is processed second."