Can you sell stocks/commodities for any price you wish (either direct or market)?
"You answered your own question ""whether someone buys is a different thing"". You can ask any price that you want. (Or given an electronic brokerage, you can enter the highest value that the system was designed to accept.) The market (demand) will determine whether anyone will buy at the price you are asking. A better strategy if you want to make an unreasonable amount of money is to put in a buy order at an unreasonably low price and hope a glitch causes a flash crash and allows you to purchase at that price. There may be rules that unravel your purchase after the fact, but it has a better chance of succeeding than trying to sell at an unreasonably high price." "In other words, does the market have control over sale numbers or do I? You both do, just like for the bike.  You have control over the price you ask, and the buyer has control over the price they pay.  If the two do not align, no sale takes place. Your question uses the words ""sell"" and ""sale"" ambiguously.  You can decide to ask for any price you want.  You cannot actually sell anything until someone agrees to buy what you are offering." "I think for this a picture is worth a thousand words.  This is a ""depth chart"" that I pulled from google images, specifically because it doesn't name any security.  On the left you have all of the ""bids"" to buy this security, on the right you have the ""asks"" to sell the security.  In the middle you have the bid/ask spread, this is the space between the highest bid and the lowest ask.  As you can see you are free to place you order to the market to buy for 232, and someone else is free to place their order to the market to sell for 234.  When the bid and the ask match there's a transaction for the maximum number of available shares.  Alternatively, someone can place a market order to buy or sell and they'll just take the current market price. Retail investors don't really get access to this kind of chart from their brokers because for the most part the information isn't terribly relevant at the retail level."
"Probably the biggest driver of the increased volumes that day was a change in sentiment towards the healthcare sector as a whole that caused many healthcare companies to experience higher volumes ( https://www.bloomberg.com/press-releases/2017-07-11/asset-acquisitions-accelerate-in-healthcare-sector-boosting-potential-revenue-growth ). Following any spike, not just sentiment related spikes, the market tends to bounce back to about where it had been previously as analysts at the investment banks start to see the stock(s) as being overbought or oversold. This is because the effect of a spike on underlying ratios such as the Sharpe ratio or the PE ratio makes the stock look less attractive to buyers and more attractive to sellers, including short sellers. Note, however, that the price is broadly still a little higher than it was before the spike as a result of this change in sentiment. Looking at the price trends on Bloomberg (https://www.bloomberg.com/quote/CDNA:US) the price had been steadily falling for the year prior to the spike but was levelling out at just over $1 in the few months immediately prior to the spike. The increased interest in the sector and the stock likely added to a general change in the direction of the price trend and caused traders (as opposed to investors) to believe that there was a change in the price trend. This will have lead to them trading the stock more heavily intraday exacerbating the spike. Note that there traders will include HFT bots as well as human traders. You question the legality of this volume increase but the simple answer is that we may never know if it was the target of traders manipulating the price or a case of insider trading. What we can see is that (taking ""animal spirits"" into account) without any evidence of illegality there are plenty of potential reasons why the spike may have occurred. Spikes are common where traders perceive a change in a trend as they rush to cash in on the change before other traders can and then sell out quickly when they realise that the price is fundamentally out of sync with the firm's underlying position. You yourself say that you have been watching the stock for some time and, by that fact alone, it is likely that others are for the same reasons that you are. Otherwise you wouldn't be looking at it. Where people are looking at a stock expecting it to take off or drop you expect volatility and volatility means spikes!" "In general, I think you're conflating a lot of ideas.   The stock market is not like a supermarket.  With the exception of a direct issue, you're not buying your shares from the company or from the New York Stock Exchange you're buying from an owner of stock, Joe, Sally, a pension fund, a hedge fund, etc; it's not sitting on a shelf at the stock market. When you buy an Apple stock you don't own $10 of Apple, you own 1/5,480,000,000th of Apple because Apple has 5,480,000,000 shares outstanding.  When a the board gets together to vote on and approve a dividend the approved dividend is then divided by 5.48 billion to determine how much each owner receives.  The company doesn't pay dividends out to owners from a pot of money it received from new owners; it sold iPhones at a profit and is sending a portion of that profit to the owners of the company.   ""When you buy stock, it is claimed that you own a small portion of the   company. This statement has no backing, as you cannot exchange your   stock for the company's assets."" The statement does have backing.  It's backed by the US Judicial system.  But there's a difference between owning a company and owning the assets of the company.  You own 1/5,480,000,000 of the company and the company owns the company's assets.  Nevermind how disruptive it would be if any shareholder could unilaterally decide to sell a company's buildings or other assets. This is not a ponzi scheme because when you buy or sell your Apple stock, it has no impact on Apple, you're simply transacting with another random shareholder (barring a share-repurchase or direct issue).  Apple doesn't receive the proceeds of your private transaction, you do. As far as value goes, yes the stock market provides tons of value and is a staple of capitalism.  The stock market provides an avenue of financing for companies.  Rather than taking a loan, a company's board can choose to relinquish some control and take on additional owners who will share in the spoils of the enterprise.   Additionally, the exchanges deliver value via an unbelievable level of liquidity.  You don't have to go seek out Joe or Sally when you want to sell your Apple stock.  You don't need to put your shares on Craigslist in the hope of finding a buyer.  You don't have to negotiate a price with someone who knows you want to sell.  You just place an order at an exchange and you're aligned with a buyer.   Also understand that anything can move up or down in value without any money actually changing hands.  Say you get your hands on a pair of shoes (or whatever), they're hot on the market, very rare and sought after.  You think you can sell them for $1,000. On tonight's news it turns out that the leather is actually from humans and the CEO of the company is being indicted, the company is falling apart, etc.  Your shoes just went from $1,000 to $0 with no money changing hands (or from $1,000 to $100,000 depending on how cynical you are)." "For a non-ETF mutual fund, you can only buy shares of the mutual fund from the mutual fund itself (at a price that the mutual fund will reveal only at the end of the day) and can only shares back to the mutual fund (again at a price that the mutual fund will reveal only at the end of the day). There is no open market in the sense that you cannot put in a bid to buy, say, 100 shares of VFINX at $217 per share through a brokerage, and if there is a seller willing to sell 100 shares of VFINX to you at $217, then the sale is consummated and you are now the proud owner of 100 shares of VFINX. The only buyer or seller of VFINX is the mutual find itself, and you tell it that you ""want to buy 100 shares of VFINX and please take the money out of my checking account"". If this order is entered before the markets close at 4 pm, the mutual fund determines its share price as of the end of the day, opens a new account for you and puts 100 shares of VFINX in it (or adds 100 shares of VFINX to your already existing pile of shares) and takes the purchase price out of your checking account via an ACH transfer. Similarly for redeeming/selling shares of VFINX that you own (and these are held in an account at the mutual fund itself, not by your brokerage): you tell the mutual fund to that you ""wish to redeem 100 shares and please send the proceeds to my bank account"" and the mutual fund does this at the end of the day, and the money appears in your bank account via ACH transfer two or three days later.  Generally, these transactions do not need to be for round lots of multiples of 100 shares for efficiency; most mutual fund will gladly sell you fractional shares down to a thousandth of a share. In contrast, shares of an exchange-traded fund (ETF) are just like stock shares in that they can be bought and sold on the open market and your broker will charge you fees for buying and selling them. Selling fractional shares on the open market is generally not possible, and trading in round lots is less expensive. Also, trades occur at all times of the stock exchange day, not just at the end of the day as with non-ETF funds, and the price can fluctuate during the day too. Many non-ETF mutual funds have an ETF equivalent: VOO is the symbol for Vanguard's S&P 500 Index ETF while VFINX is the non-ETF version of the same index fund.  Read more about the differences between ETFs and mutual funds, for example, here." "There are two distinct questions that may be of interest to you. Both questions are relevant for funds that need to buy or sell large orders that you are talking about. The answer depends on your order type and the current market state such as the level 2 order book. Suppose there are no iceberg or hidden orders and the order book (image courtesy of this question) currently is:  An unlimited (""at market"") buy order for 12,000 shares gets filled immediately: it gets 1,100 shares at 180.03 (1,100@180.03), 9,700 at 180.04 and 1,200 at 180.05. After this order, the lowest ask price becomes 180.05 and the highest bid is obviously still 180.02 (because the previous order was a 'market order'). A limited buy order for 12,000 shares with a price limit of 180.04 gets the first two fills just like the market order: 1,100 shares at 180.03 and 9,700 at 180.04. However, the remainder of the order will establish a new bid price level for 1,200 shares at 180.04. It is possible to enter an unlimited buy order that exhausts the book. However, such a trade would often be considered a mis-trade and either (i) be cancelled by the broker, (ii) be cancelled or undone by the exchange, or (iii) hit the maximum price move a stock is allowed per day (""limit up""). Funds and banks often have to buy or sell large quantities, just like you have described. However they usually do not punch through order book levels as I described before. Instead they would spread out the order over time and buy a smaller quantity several times throughout the day. Simple algorithms attempt to get a price close to the time-weighted average price (TWAP) or volume-weighted average price (VWAP) and would buy a smaller amount every N minutes. Despite splitting the order into smaller pieces the price usually moves against the trader for many reasons. There are many models to estimate the market impact of an order before executing it and many brokers have their own model, for example Deutsche Bank. There is considerable research on ""market impact"" if you are interested. I understand the general principal that when significant buy orders   comes in relative to the sell orders price goes up and when a   significant sell order comes in relative to buy orders it goes down. I consider this statement wrong or at least misleading. First, stocks can jump in price without or with very little volume. Consider a company that releases a negative earnings surprise over night. On the next day the stock may open 20% lower without any orders having matched for any price in between. The price moved because the perception of the stocks value changed, not because of buy or sell pressure. Second, buy and sell pressure have an effect on the price because of the underlying reason, and not necessarily/only because of the mechanics of the market. Assume you were prepared to sell HyperNanoTech stock, but suddenly there's a lot of buzz and your colleagues are talking about buying it. Would you still sell it for the same price? I wouldn't. I would try to find out how much they are prepared to buy it for. In other words, buy pressure can be the consequence of successful marketing of the stock and the marketing buzz is what changes the price." No you can't, as you would have to have a different order for each security. Usually the bigger the order the more the brokerage you would also pay. I would not argue if its more difficult, its different, and it much depends what kind of stocks you refer to, i take large caps as example. The players are different. Companies and even govts may hedge in the commodities (futures) market while in big caps this and other entities mainly invest. (Of course there’s HFT in large caps too). Futures often come with way higher leverage, lower spread and less commissions than stocks attracting retail and institutional speculators/HFT. Another big difference is that commodity prices react to all kind of news events (Stocks do too, but not that much and frequent), this kind of reactions big caps only do on earnings or on news directly affecting the company. Commodities are much more volatile on geo economic / political news events. This combined with higher leverage & HFT produces astounding moves.  To sum it up, the players are different and act different than in large stocks, liquidity may be another thing. No, Mark is right, if you place a market order there will always be someone to buy or sell at the market price.  Only if you place a limit order on the price can it not sell or be bought.  Just research on your computer and you will find your answer.  You must be specify about open order or limit order when asking. At any point of time, buyer wants to purchase a stock at lesser price and seller wants to sell the stock at a higher price.  Let's consider this scenario  Company XYZ is trading at 100$, as stated above buyer wants to purchase at lower price and seller at higher price, this information will be available in Market depth, let's consider there are 5 buyers and 5 sellers, below are the details of their orders Buyers List Sellers List Highest order in buyers list will contain the bid price and bid quantity, Lowest order in Sellers list will contain the offer price and offer quantity. Now, if I want to buy 50 Stocks of company XYZ, need to place an order first, it can be either limit or Market. Limit Order : In this order, I will mention the price(buy price) at which I wish to buy, if there is any seller selling the stock less than or equal to price I have mentioned, then the order will be executed else it will be added to buyers list Market Order : In this order, I will not mention the price, if I wish to purchase 50 Stocks, then it will find the lowest offer price and buy stocks, in our case it will be 101. if I wish to purchase 200 Stocks, then it will find the lowest offer price and buy stocks, in our case it will be 2 transactions, since entire request cannot be accommodated in single order Usually the volume(Ask Volume and Offer Volume) being displayed are all Limit orders and not Market orders, Market orders are executed immediately. This is just an example, However several transactions are executed within a second, hence we will get to know the exact value only after the order is completed(executed)