Is it possible to lower the price of a stock while buying?
"You can choose to place successively lower buy limit orders, but whether they get filled or not is not a given; it depends on whether sellers care to accept your bid. In your example of a 49.98 / 50.01 spread, if you place a buy with limit of 49.99, it won't get filled (if the order reaches the market while still at 49.98 / 50.01) immediately, but will be added to the order book.  By being added to the order book, the markets bid and ask become 49.99 / 50.01.  Your order won't get filled until some seller places a market order or a sell limit order of 49.99 or less.  No guarantee that that will happen, and even if it does, there's nothing to say that your follow-up buy at 49.98 will ever be filled.  In fact, your 49.98 buy order queues up at the ""end of the line"" behind all previously pending 49.98 bids, since your order arrived after those other bids.  Since the initial conditions you supposed had a 49.98 bid, such an order exists (or at least did exist; it might have been cancelled in the intervening moment. Basically, your first buy at 49.99, if it happens, has essentially no influence on whether your second buy at 49.98 will happen.  You can't expect to move the market lower by making a bid that is higher (49.99) than the existing best bid (49.98).  Whatever influence your 49.99 order has is to raise the market's price, not lower it." The strategy could conceivably work if you had sufficient quantity of shares to fill all of the outstanding buy orders and fill your lower buy orders.  But in this case you are forcing the market down by selling and reinforcing the notion that there is a sell off by filling ever lower buy orders.  There is the potential to trigger some stop loss orders if you can pressure it low enough.  There is a lot of risk here that someone sees what you are doing and decides to jump in and buy forcing the price back up.  Could this work sure.  But it is very risky and if you fail to create the panic selling then you risk losing big.  I also suspect that this would violate SEC Rules and several laws.  And if the price drops too far then trading on the stock would be halted and is likely to return at the appropriate price. Bottom line I can not see a scenario where you do not trigger the stop, net a profit and end up with as many or more stock that you had in the first place.
"Vitalik has mentioned this in a comment but I think it ought to be expanded upon: Companies that aren't already penny stocks really don't stand to gain anything from trying to prevent short interest.  Short selling does not inherently lower the stock price - not any more so than any other kind of selling.  When somebody shorts a stock, it's simply borrowed from another investor's margin; as long as it's not a naked short resulting in an FTD (Failure To Deliver) then it does not add any ""artificial"" selling pressure. In fact, shorting can actually drive the price up in the long term due to stops and margin calls.  Not a guarantee, of course, but if a rally occurs then a high short interest can cause a cascade effect from the short ""squeeze"", resulting in an even bigger rally than what would have occurred with zero short interest.  Many investors actually treat a high short interest as a bullish signal. Compare with margin buying - essentially the opposite of short selling - which has the opposite effect.  If investors buy stocks on margin, then if the value of that stock decreases too rapidly they will be forced to sell, which can cause the exact same cascade effect as a short interest but in the opposite direction.  Shorting is (in a sense) evening out the odds by inflating the buying pressure at lower stock prices when the borrowers decide to cover and take profits. Bottom line is that, aside from (illegal) insider trading, it doesn't do businesses any good to try to manipulate their stock price or any trading activity.  Yes, a company can raise capital by selling additional common shares, but a split really has no effect on the amount of capital they'd be able to raise because it doesn't change the actual market cap, and a dilution is a dilution regardless of the current stock price.  If a company's market cap is $1 billion then it doesn't matter if they issue 1 million shares at $50.00 each or 10 million shares at $5.00 each; either way it nets them $50 million from the sale and causes a 5% dilution, to which the market will react accordingly. They don't do it because there'd be no point." In this type of strategy profit is made when the shares go down as your main position is the short trade of the common stock. The convertible instruments will tend to move in about the same direction as the underlying (what it can be converted to) but less violently as they are traded less (lower volatility and lower volume in the market on both sides), however, they are not being used to make a profit so much as to hedge against the stock going up. Since both the bonds and the preference shares are higher on the list to be repaid if the company declares bankruptcy and the bonds pay out a fixed amount of interest as well, both also help protect against problems that may occur with a long position in the common stock.  Essentially the plan with this strategy is to earn fixed income on the bonds whilst the stock price drops and then to sell both the bonds and buy the stock back on the market to cover the short position. If the prediction that the stock will fall is wrong then you are still earning fixed income on the debt and are able to convert it into stock at the higher price to cover the short sale eliminating, or reducing, the loss made on the short sale. Effectively the profit here is made on the spread between the price of the bond, accounting for the conversion price, and the price of the stock and that fixed income is less volatile (except usually in the junk market) than stock. Firstly what are you trading that you could lose more than you put in? If you are simply trading stocks you will not lose more than you put in, unless you are trading on margin. A limit order is basically that, a limit on the maximum price you want your buy order bought at or the minimum price you want your sell order sold at. If you can't be glued to the screen all day when you place a limit order, and the market moves the opposite way, you may miss out on your order being executed. Even if you can be in front of the screen all day, you then have to decide if you want to chase the market of miss out on your purchase or sale. For example, if a stock is trading at $10.10 and you put a limit buy order to buy 1000 shares at or below $10.00 and the price keeps moving up to $10.20, then $10.30 and then $10.50, until it closes the day at $11.00. You then have the choice during the day to miss out on buying the shares or to increase your limit order in order to buy at a higher price. Sometime if the stock is not very liquid, i.e. it does not trade very often and has low volume, the price may hit $10.00 and you may only have part of your order executed, say 500 out of your 1000 shares were bought. This may mean that you may have to increase the price of your remaining order or be happy with only buying 500 shares instead of 1000. The same can happen when you are selling (but in reverse obviously). With market order, however, you are placing a buy order to buy at the next bid price in the depth or a sell order to sell at the next offer price in the depth. See the market depth table below:  Note that this price depth table is taken before market open so it seems that the stock is somewhat illiquid with a large gap between the first and second prices in the buyers (bid) prices. When the market opened this gap is closed, as WBC is a major Australian bank and is quite liquid. (the table is for demonstration purposes only). If we pretend that the market was currently open and saw the current market depth for WBC as above, you could decide to place a limit sell order to sell 1000 shares at say $29.91. You would sell 100 shares straight away but your remaining 900 sell order will remain at the top of the Sellers list. If other Buyers come in at $29.91 you may get your whole sale completed, however, if no other Buyers place orders above $29.80 and other Sellers come into the market with sell orders below $29.91, your remaining order may never be executed. If instead you placed a market sell order you would immediately sell 100 shares at $29.91 and the remaining 900 shares at $29.80. (so you would be $99 or just over 0.3% worse off than if you were able to sell the full 1000 shares at $29.91). The question is how low would you have had to lower your limit order price if the price for WBC kept on falling and you had to sell that day? There are risks with whichever type of order you use. You need to determine what the purpose of your order is. Is it to get in or out of the market as soon as possible with the possibility of giving a little bit back to the market? Or is it to get the price you want no matter how long it takes you? That is you are willing to miss out on buying the shares (can miss out on a good buy if the price keeps rising for weeks or months or even years) or you are willing to miss out on selling them right now and can wait for the price to come back up to the price you were willing to sell at (where you may miss out on selling the shares at a good price and they keep on falling and you give back all your profits and more). Just before the onset of the GFC I sold some shares (which I had bought a few years earlier at $3.40) through a market order for $5.96. It had traded just above $6 a few days earlier, but if instead of a market order I had placed a limit order to sell at $6.00 or more I would have missed out on the sale. The price never went back up  to $6 or above, and the following week it started dropping very quickly. It is now trading at about $1.30 and has never gone back above $2.00 (5.5 years later). So to me placing a limit order in this case was very risky. Yes, theoretically you can flip the shares you agreed to buy and make a profit, but you're banking on the market behaving in some very precise and potentially unlikely ways.  In practice it's very tricky for you to successfully navigate paying arbitrarily more for a stock than it's currently listed for, and selling it back again for enough to cover the difference.  Yes, the price could drop to $28, but it could just as easily drop to $27.73 (or further) and now you're hurting, before even taking into account the potentially hefty commissions involved. Another way to think about it is to recognize that an option transaction is a bet; the buyer is betting a small amount of money that a stock will move in the direction they expect, the seller is betting a large amount of money that the same stock will not.  One of you has to lose.  And unless you've some reason to be solidly confident in your predictive powers the loser, long term, is quite likely to be you. Now that said, it is possible (particularly when selling puts) to create win-win scenarios for yourself, where you're betting one direction, but you'd be perfectly happy with the alternative(s).   Here's an example.  Suppose, unrelated to the option chain, you've come to the conclusion that you'd be happy paying $28 for BBY.  It's currently (June 2011) at ~$31, so you can't buy it on the open market for a price you'd be happy with.  But you could sell a $28 put, promising to buy it at that price should someone want to sell it (presumably, because the price is now below $28). Either the put expires worthless and you pocket a few bucks and you're basically no worse off because the stock is still overpriced by your estimates, or the option is executed, and you receive 100 shares of BBY at a price you previously decided you were willing to pay.  Even if the list price is now lower, long term you expect the stock to be worth more than $28.  Conceptually, this makes selling a put very similar to being paid to place a limit order to buy the stock itself. Of course, you could be wrong in your estimate (too low, and you now have a position that might not become profitable; too high, and you never get in and instead just watch the stock gain in value), but that is not unique to options - if you're bad at estimating value (which is not to be confused with predicting price movement) you're doomed just about whatever you do. In order to see whether you can buy or sell some given quantity of a stock at the current bid price, you need a counterparty (a buyer) who is willing to buy the number of stocks you are wishing to offload. To see whether such a counterparty exists, you can look at the stock's order book, or level two feed. The order book shows all the people who have placed buy or sell orders, the price they are willing to pay, and the quantity they demand at that price. Here is the order book from earlier this morning for the British pharmaceutical company, GlaxoSmithKline PLC.  Let's start by looking at the left-hand blue part of the book, beneath the yellow strip. This is called the Buy side. The book is sorted with the highest price at the top, because this is the best price that a seller can presently obtain. If several buyers bid at the same price, then the oldest entry on the book takes precedence. You can see we have five buyers each willing to pay 1543.0 p (that's 1543 British pence, or £15.43) per share. Therefore the current bid price for this instrument is 1543.0. The first buyer wants 175 shares, the next, 300, and so on. The total volume that is demanded at 1543.0p is 2435 shares. This information is summarized on the yellow strip: 5 buyers, total volume of 2435, at 1543.0. These are all buyers who want to buy right now and the exchange will make the trade happen immediately if you put in a sell order for 1543.0 p or less. If you want to sell 2435 shares or fewer, you are good to go. The important thing to note is that once you sell these bidders a total of 2435 shares, then their orders are fulfilled and they will be removed from the order book. At this point, the next bidder is promoted up the book; but his price is 1542.5, 0.5 p lower than before. Absent any further changes to the order book, the bid price will decrease to 1542.5 p. This makes sense because you are selling a lot of shares so you'd expect the market price to be depressed. This information will be disseminated to the level one feed and the level one graph of the stock price will be updated. Thus if you have more than 2435 shares to sell, you cannot expect to execute your order at the bid price in one go. Of course, the more shares you are trying to get rid of, the further down the buy side you will have to go. In reality for a highly liquid stock as this, the order book receives many amendments per second and it is unlikely that your trade would make much difference. On the right hand side of the display you can see the recent trades: these are the times the trades were done (or notified to the exchange), the price of the trade, the volume and the trade type (AT means automatic trade).  GlaxoSmithKline is a highly liquid stock with many willing buyers and sellers. But some stocks are less liquid. In order to enable traders to find a counterparty at short notice, exchanges often require less liquid stocks to have market makers. A market maker places buy and sell orders simultaneously, with a spread between the two prices so that they can profit from each transaction. For instance Diurnal Group PLC has had no trades today and no quotes. It has a more complicated order book, enabling both ordinary buyers and sellers to list if they wish, but market makers are separated out at the top. Here you can see that three market makers are providing liquidity on this stock, Peel Hunt (PEEL), Numis (NUMS) and Winterflood (WINS). They have a very unpalatable spread of over 5% between their bid and offer prices. Further in each case the sum total that they are willing to trade is 3000 shares. If you have more than three thousand Dirunal Group shares to sell, you would have to wait for the market makers to come back with a new quote after you'd sold the first 3000. "A big part of the answer depends on how ""beaten down"" the stock is, how long it will take to recover from the drop, and your taste for risk. If you honestly believe the drop is a temporary aberration then averaging down can be a good strategy to lower your dollar-cost average in the stock.  But this is a huge risk if you're wrong, because now you're going to magnify your losses by piling on more stock that isn't going anywhere to the shares you already own at a higher cost. As @Mindwin pointed out correctly, the problem for most investors following an ""average down"" strategy is that it makes them much less likely to cut their losses when the stock doesn't recover.  They basically become ""married"" to the stock because they've actualized their belief the stock will bounce back when maybe it never will or worse, drops even more." You want to buy when the stock market is at an all-time low for that day. Unfortunately, you don't know the lowest time until the end of the day, and then you, uh can't buy the stock... Now the stock market is not random, but for your case, we can say that effectively, it is. So, when should you buy the stock to hopefully get the lowest price for the day? You should wait for 37% of the day, and then buy when it is lower than it has been for all of that day. Here is a quick example (with fake data): We have 18 points, and 37% of 18 is close to 7. So we discard the first 7 points - and just remember the lowest of those 7. We bear in mind that the lowest for the first 37% was 5. Now we wait until we find a stock which is lower than 5, and we buy at that point: This system is optimal for buying the stock at the lowest price for the day. Why? We want to find the  best position to stop automatically ignoring. Why 37%? We know the answer to P(Being in position n) - it's 1/N as there are N toilets, and we can select just 1. Now, what is the chance we select them, given we're in position n? The chance of selecting any of the toilets from 0 to K is 0 - remember we're never going to buy then. So let's move on to the toilets from K+1 and onwards. If K+1 is better than all before it, we have this: But, K+1 might not be the best price from all past and future prices. Maybe K+2 is better. Let's look at K+2 For K+2 we have K/K+1, for K+3 we have K/K+2... So we have: This is a close approximation of the area under 1/x - especially as x → ∞   So 0 + 0 + ... + (K/N) x (1/K + 1/K+1 + 1/K+2 ... + 1/N-1) ≈ (K/N) x ln(N/K) and so P(K) ≈ (K/N) x ln(N/K) Now to simplify, say that x = K/N We can graph this, and find the maximum point so we know the maximum P(K) - or we can use calculus. Here's the graph:  Here's the calculus: To apply this back to your situation with the stocks, if your stock updates every 30 seconds, and is open between 09:30 and 16:00, we have 6.5 hours = 390 minutes = 780 refreshes. You should keep track of the lowest price for the first 289 refreshes, and then buy your stock on the next best price. Because x = K/N, the chance of you choosing the best price is 37%. However, the chance of you choosing better than the average stock is above 50% for the day. Remember, this method just tries to mean you don't loose money within the day - if you want to try to minimise losses within the whole trading period, you should scale this up, so you wait 37% of the trading period (e.g. 37% of 3 months) and then select. The maths is taken from Numberphile - Mathematical Way to Choose a Toilet. Finally, one way to lose money a little slower and do some good is with Kiva.org - giving loans to people is developing countries. It's like a bank account with a -1% interest - which is only 1% lower than a lot of banks, and you do some good. I have no affiliation with them. "Why would people sell below the current price, and not within the range of the bid/ask? There are many scenarios where this is deliberate but all of them boil down to the fact that the top level's bid doesn't support the quantity you're trying to sell (or is otherwise bogus[1]). One scenario as an example: You're day-trading both sides but at the end of the day you accumulated a rather substantial long position in a stock.  You don't want to (or aren't allowed to[2]) be exposed overnight, however.  What do you do? You place an order that is highly likely to go through altogether.  There's several ways to achieve that but a very simple one is to look at the minimum bid level for which the bid side is willing to take all of your shares, then place a limit order for the total quantity at that price.  If your position doesn't fit into the top level bid that price will well be lower than the ""current"" bid. Footnotes: [1] Keyword: quote stuffing [2] Keyword: overnight margin (aka positional margin, as opposed to intraday margin), this is highly broker dependent, exchanges don't usually distinguish between intraday and overnight margins, instead they use the collective term maintenance margin"