Why is the price of my investment only updated once per day?
Mutual funds are collections of investments that other people pay to join.  It would be simpler to calculate the value of all these investments at one time each day, and then to deem that any purchases or sales happen at that price.  The fund diversifies rather than magnifies risk, looking to hold rather than enjoy a quick turnaround.  Nobody really needs hourly updated price information for an investment they intend to hold for decades. They quote their prices on a daily basis and you take the daily price.  This makes sense for a vehicle that is a balanced collection of many different assets, most of which will have varying prices over the course a day.  That makes pricing complicated.  This primer explains mutual fund pricing and the requirements of the Investment Company Act of 1940, which mandates daily price reporting.  It also illustrates the complexity: How does the fund pricing process work? Mutual fund pricing is an intensive process that takes place in a short time frame at the end of the day. Generally, a fund’s pricing process begins at the close of the New York Stock Exchange, normally 4 p.m. Eastern time. The fund’s accounting agent, which may be an affiliated entity such as the fund’s adviser, or a third-party servicer such as the fund’s administrator or custodian bank, is usually responsible for calculating the share price. The accounting agent obtains prices for the fund’s securities from pricing services and directly from brokers. Pricing services collect securities prices from exchanges, brokers, and other sources and then transmit them to the fund’s accounting agent. Fund accounting agents internally validate the prices received by subjecting them to various control procedures. For example, depending on the nature and extent of its holdings, a fund may use one or more pricing services to ensure accuracy. Note that under Rule 22c-1 forward pricing, fund shareholders receive the next daily price, not the last daily price.  Forward pricing makes sense if you want shareholders to get the most accurate sale or purchase price, but not if you want purchasers and sellers to be able to make precise calculations about gains and losses (how can you be precise if the price won't be known until after you buy or sell?). Mutual funds are only traded once per day, while other securities can be traded any time during the day. Mutual funds are actually a collection of other things that have value, such as stocks. The price of a mutual fund is calculated at the end of the day after the market closes by looking at how much the collection of things changed in value during the day. I strongly suggest you go to www.investor.gov as it has excellent information regarding these types of questions. A mutual fund is a company that pools money from many investors and invests the money in securities such as stocks, bonds, and short-term debt. The combined holdings of the mutual fund are known as its portfolio. Investors buy shares in mutual funds. Each share represents an investor’s part ownership in the fund and the income it generates. When you buy shares of a mutual fund you're buying it at NAV, or net asset value.  The NAV is the value of the fund’s assets minus its liabilities. SEC rules require funds to calculate the NAV at least once daily. Different funds may own thousands of different stocks.  In order to calculate the NAV, the fund company must value every security it owns.  Since each security's valuation is changing throughout the day it's difficult to determine the valuation of the mutual fund except for when the market is closed.  Once the market has closed (4pm eastern) and securities are no longer trading, the company must get accurate valuations for every security and perform the valuation calculations and distribute the results to the pricing vendors.  This has to be done by 6pm eastern.  This is a difficult and, more importantly, a time consuming process to get it done right once per day.  Having worked for several fund companies I can tell you there are many days where companies are getting this done at the very last minute. When you place a buy or sell order for a mutual fund it doesn't matter what time you placed it as long as you entered it before 4pm ET.  Cutoff times may be earlier depending on who you're placing the order with.  If companies had to price their funds more frequently, they would undoubtedly raise their fees. Mutual funds are a collection of other assets, such as stocks, bonds and property. Unless the fund is a type that is traded on an exchange, you will only be able to buy into the fund by applying for units with the fund manager and sell out by contacting the fund manager. These type of non-traded funds are usually updated at the end of the day once the closing prices of all the assets in it are known. "There is no fundamental, good reason, I think; ""that's just how it's done"" (which is what all the other answers seem to be saying, w/o coming out and admitting it). Just guessing, but I'll bet most of the reason is historical: Before up-to-the-moment quotes were readily available, that was a bit tedious to calculate/update the fund's value, so enacted-laws let it be done just once per day.  (@NL7 quotes the security act of 1940, which certainly has been updated, but also still might contain the results of crufty rationales, like this.) There are genuinely different issues between funds and stocks, though: One share of a fund is fundamentally different from one share of stock: There is a finite supply of Company-X-stock, and people are trading that piece of ownership around, and barter to find an mutually-agreeable-price.  But when you buy into a mutual-fund, the mutual-fund ""suddenly has more shares"" -- it takes your money and uses it to buy shares of the underlying stocks (in a ratio equal to its current holdings).  As a consequence: the mutual fund's price isn't determined by two people bartering and agreeing on a price (like stock); there is exactly one sane way to price a mutual fund, and that's the weighted total of its underlying stock.  If you wanted to sell your ownership-of-Mutual-Fund-Z to a friend at 2:34pm, there wouldn't be any bartering, you'd just calculate the value based on the stated-value of the underlying stock at that exact moment. So: there's no inherent reason you can't instantaneously price a mutual fund.  BUT people don't really buy/sell funds to each other -- they go to the fund-manager and essentially make a deposit-or-withdraw.  The fund-manager is only required by law to do it once a day (and perhaps even forbidden from doing it more often?), so that's all they do. [Disclaimer: I know very little about markets and finance. But I recognize answers that are 'just because'.]"
"I too am a full-monthly-statement-balance payer and I received a balance transfer offer from my credit-card company. This one was quite different from many others that I have read about on this forum. I could do a balance transfer for any amount up to $X from another credit card, or use the enclosed ""checks"" to pay  some other (non-credit-card) bills, and I would not have to pay any interest for 12 months on the amount thus borrowed.  But, There would be a 2% service charge on the amount I was borrowing. This amount would be billed on the next monthly statement, and it would have to be paid in full by the due date of that month's payment, that is, within the 25-day grace period allowed for payment of monthly statements. Else, interest would start being charged on the unpaid part of the service charge at the usual humongous rate of H% per month. If I had not paid the previous month's balance in full, I would be charged interest at H% per month on the service charge starting from Day One; no free ride till the due date of the next month's statement. Of course, the balance carried over from last month would also be charged interest at H%. If I had paid last month's bill in full, but there were any other charges (purchases) during the current month, then  unless the entire amount due, this month's purchases plus service charge and that ""interest-free-for-twelve-months loan""  balance was paid off within the 25-day grace period, my purchases would be deemed unpaid and would start being charged interest. In short, the only way to avoid paying interest on the amount borrowed was to start with a card showing a $0 balance due on the previous month's statement, not make any charges on that card for a whole year, and pay off that 2% service charge within the grace period. It might also have required that one-twelfth of that interest-free loan be repaid each month, but  I had stopped reading the offer at this point and filed it in the round circular file. In short, while @JoeTaxpayer's tale of how ""As a pay-in-full user, I've used the zero rate to throw $20K at the 5.25% mortgage"" is undoubtedly how things worked once, it is not at all clear that they still work that way. At least, they don't work that way for me.  Heck, once upon a time, for a period of about 3 months, you could earn 1.5% interest per month from the credit card company by overpaying your credit card bill considerably. Their computers then just ""added on"" 1.5% interest by multiplying your credit balance -$X by 1.015 and so you got 1.5% per month interest from the credit card company. The credit card agreements (and the software!) got changed in a hurry, and nowdays all credit-card agreements state in the fine print that if you overpay your bill, you don't earn any interest on the overpayment." "Zero? Ten grand? Somewhere in the middle? It depends. Your stated salary, in U.S. dollars, would be high five-figures (~$88k). You certainly should not be starving, but with decent contributions toward savings and retirement, money can indeed be tight month-to-month at that salary level, especially since even in Cardiff you're probably paying more per square foot for your home than in most U.S. markets (EDIT: actually, 3-bedroom apartments in Cardiff, according to Numbeo, range from £750-850, which is US$1200-$1300, and for that many bedrooms you'd be hard-pressed to find that kind of deal in a good infield neighborhood of the DFW Metro, and good luck getting anywhere close to downtown New York, LA, Miami, Chicago etc for that price. What job do you do, and how are you expected to dress for it? Depending on where you shop and what you buy, a quality dress shirt and dress slacks will cost between US$50-$75 each (assuming real costs are similar for the same brands between US and UK, that's £30-£50 per shirt and pair of pants for quality brands). I maintain about a weeks' wardrobe at this level of dress (my job allows me to wear much cheaper polos and khakis most days and I have about 2 weeks' wardrobe of those) and I typically have to replace due to wear or staining, on average, 2 of these outfits a year (I'm hard on clothes and my waistline is expanding). Adding in 3 ""business casual"" outfits each year, plus casual outfits, shoes, socks, unmentionables and miscellany, call it maybe $600(£400)/year in wardrobe. That doesn't generally get metered out as a monthly allowance (the monthly amount would barely buy a single dress shirt or pair of slacks), but if you're socking away a savings account and buying new clothes to replace old as you can afford them it's a good average. I generally splurge in months when the utilities companies give me a break and when I get ""extra"" paychecks (26/year means two months have 3 checks, effectively giving me a ""free"" check that neither pays the mortgage nor the other major bills). Now, that's just to maintain my own wardrobe at a level of dress that won't get me fired. My wife currently stays home, but when she worked she outspent me, and her work clothes were basic black. To outright replace all the clothes I wear regularly with brand-new stuff off the rack would easily cost a grand, and that's for the average U.S. software dev who doesn't go out and meet other business types on a daily basis. If I needed to show up for work in a suit and tie daily, I'd need a two-week rotation of them, plus dress shirts, and even at the low end of about $350 (£225) per suit, $400 (£275) with dress shirt and tie, for something you won't be embarrassed to wear, we're talking $4000 (£2600) to replace and $800 (£520) per year to update 2 a year, not counting what I wear underneath or on the weekends. And if I wore suits I'd probably have to update the styles more often than that, so just go ahead and double it and I turn over my wardrobe once every 5 years. None of this includes laundering costs, which increase sharply when you're taking suits to the cleaners weekly versus just throwing a bunch of cotton-poly in the washing machine. What hobbies or other entertainment interests do you and your wife have? A movie ticket in the U.S. varies between $7-$15 depending on the size of the screen and 2D vs 3D screenings. My wife and I currently average less than one theater visit a month, but if you took in a flick each weekend with your wife, with a decent $50 dinner out, that's between $260-$420 (£165-270) monthly in entertainment expenses. Not counting babysitting for the little one (the going rate in the US is between $10 and $20 an hour for at-home child-sitting depending on who you hire and for how long, how often). Worst-case, without babysitting that's less than 5% of your gross income, but possibly more than 10% of your take-home depending on UK effective income tax rates (your marginal rate is 40% according to the HMRC, unless you find a way to deduct about £30k of your income). That's just the traditional American date night, which is just one possible interest. Playing organized sports is more or less expensive depending on the sport. Soccer (sorry, football) just needs a well-kept field, two goals and and a ball. Golf, while not really needing much more when you say it that way, can cost thousands of dollars or pounds a month to play with the best equipment at the best courses. Hockey requires head-to-toe padding/armor, skates, sticks, and ice time. American football typically isn't an amateur sport for adults and has virtually no audience in Europe, but in the right places in the U.S., beginning in just a couple years you'd be kitting your son out head-to-toe not dissimilar to hockey (minus sticks) and at a similar cost, and would keep that up at least halfway through high school. I've played them all at varying amateur levels, and with the possible exception of soccer they all get expensive when you really get interested in them. How much do you eat, and of what?. My family of three's monthly grocery budget is about $300-$400 (£190-£260) depending on what we buy and how we buy it. Americans have big refrigerators (often more than one; there's three in my house of varying sizes), we buy in bulk as needed every week to two weeks, we refrigerate or freeze a lot of what we buy, and we eat and drink a lot of high-fructose corn-syrup-based crap that's excise-taxed into non-existence in most other countries. I don't have real-world experience living and grocery-shopping in Europe, but I do know that most shopping is done more often, in smaller quantities, and for more real food. You might expect to spend £325 ($500) or more monthly, in fits and starts every few days, but as I said you'd probably know better than me what you're buying and what it's costing. To educate myself, I went to mysupermarket.co.uk, which has what I assume are typical UK food prices (mostly from Tesco), and it's a real eye-opener. In the U.S., alcohol is much more expensive for equal volume than almost any other drink except designer coffee and energy drinks, and we refrigerate the heck out of everything anyway, so a low-budget food approach in the U.S. generally means nixing beer and wine in favor of milk, fruit juices, sodas and Kool-Aid (or just plain ol' tap water). A quick search on MySupermarkets shows that wine prices average a little cheaper, accounting for the exchange rate, as in the States (that varies widely even in the U.S., as local and state taxes for beer, wine and spirits all differ). Beer is similarly slightly cheaper across the board, especially for brands local to the British Isles (and even the Coors Lite crap we're apparently shipping over to you is more expensive here than there), but in contrast, milk by the gallon (4L) seems to be virtually unheard of in the UK, and your half-gallon/2-liter jugs are just a few pence cheaper than our going rate for a gallon (unless you buy ""organic"" in the US, which carries about a 100% markup). Juices are also about double the price depending on what you're buying (a quart of ""Innocent"" OJ, roughly equivalent in presentation to the U.S. brand ""Simply Orange"", is £3 while Simply Orange is about the same price in USD for 2 quarts), and U.S.-brand ""fizzy drinks"" are similarly at a premium (£1.98 - over $3 - for a 2-liter bottle of Coca-Cola). With the general preference for room-temperature alcohol in Europe giving a big advantage to the longer unrefrigerated shelf lives of beer and wine, I'm going to guess you guys drink more alcohol and water with dinner than Americans. Beef is cheaper in the U.S., depending on where you are and what you're buying; prices for store-brand ground beef (you guys call it ""minced"") of the grade we'd use for hamburgers and sauces is about £6 per kilo in the UK, which works out to about $4.20/lb, when we're paying closer to $3/lb in most cities. I actually can't remember the last time I bought fresh chicken on the bone, but the average price I'm seeing in the UK is £10/kg ($7/lb) which sounds pretty steep. Anyway, it sounds like shopping for American tastes in the UK would cost, on average, between 25-30% more than here in the US, so applying that to my own family's food budget, you could easily justify spending £335 a month on food." &gt;Sometimes that requires more time other times less.  Oh bullshit.  Once when I had little work I started doing few hours.  After a couple weeks of this I was explicitly reprimanded and told to give 8 hours per day of butt-in-seat.  I asked if my actual team leader had complained I wasn't working efficiently enough.  Turns out he thought I was doing *just fine* for the workload he was giving me.  Only as a salaried contractor working remotely did I end up being able to turn my ability to *get my shit done* into more free time. The shift to trading at the close began in 2008. Traders did not want to be caught off guard by surprise news and there was a lot of volatility during the financial crisis, so they would close their position in the evening. Thats how it began. There are two reasons why it sticks around. First, there has been an increase usage of index funds or passive funds. These funds tend to update their positions at the end of the day. From the WSJ: Another factor behind the shift has been the proliferation of passively managed investments, such as index funds. These funds aim to mimic an index, like the S&P 500, by owning the shares that comprise it. Index funds don’t trade as often as active investors, but when they do, it is typically near the market close, traders say. That is because buying or selling a stock at its closing price better aligns their performance with the index they are trying to emulate. The second reason is simply that volume attracts volume. As a result of whats mentioned above, you have a shift to end of day trading, and the corrolary to that is that there is a liquidity shortage from 10am to 3pm. Thus, if you want to buy or sell a stock, but there are few buyers or sellers around, you will significant move the price when you enter your order. Obviously this does not affect retail traders, but imagine hedge funds entering or closing a billion dollar position. It can make a huge impact on price. And one way to mitigate that is to wait until there are more market participants to take the other end of your trade, just as at the end of the day. So this is a self-reinforcing trend that has begun in the markets and will likely stick around. http://www.wsj.com/articles/traders-pile-in-at-the-close-1432768080 Previously, Google had a delayed update for their stock prices (15 minutes I believe). That change enabled users of Google Finance to see updates to stock prices in real-time. "Remember that in most news outlets journalists do not get to pick the titles of their articles.  That's up to the editor.  So even though the article was primarily about ETFs, the reporter made the mistake of including some tangential references to mutual funds.  The editor then saw that the article talked about ETFs and mutual funds and -- knowing even less about the subject matter than the reporter, but recognizing that more readers' eyeballs would be attracted to a headline about mutual funds than to a headline about ETFs -- went with the ""shocking"" headline about the former. In any case, as you already pointed out, ETFs need to know their value throughout the day, as do the investors in that ETF.  Even momentary outages of price sources can be disastrous. Although mutual funds do not generally make transactions throughout the day, and fund investors are not typically interested in the fund's NAV more than once per day, the fund managers don't just sit around all day doing nothing and then press a couple buttons before the market closes.  They do watch their NAV very closely during the day and think very carefully about which buttons to press at the end of the day.  If their source of stock price data goes offline, then they're impacted almost as severely as -- if less visibly than -- an ETF. Asking Yahoo for prices seems straightforward, but (1) you get what you pay for, and (2) these fund companies are built on massive automated infrastructures that expect to receive their data from a certain source in a certain way at a certain time.  (And they pay a lot of money in order to be able to expect that.)  It would be quite difficult to just feed in manual data, although in the end I suspect some of these companies did just that.  Either they fell back to a secondary data supplier, or they manually constructed datasets for their programs to consume." "Firstly, if a stock costs $50 this second, the bid/ask would have to be 49/50.  If the bid/ask were 49/51, the stock would cost $51 this second.  What you're likely referring to is the last trade, not the cost.  The last trading price is history and doesn't apply to future transactions. To make it simple, let's define a simple order book.  Say there is a bid to buy 100 at $49, 200 at $48, 500 at $47.  If you place a market order to sell 100 shares, it should all get filled at $49.  If you had placed a market order to sell 200 shares instead, half should get filled at $49 and half at $48.  This is, of course, assuming no one else places an order before you get yours submitted.  If someone beats you to the 100 share lot, then your order could get filled at lower than what you thought you'd get.  If your internet connection is slow or there is a lot of latency in the data from the exchange, then things like this could happen.  Also, there are many ECNs in addition to the exchanges which may have different order books.  There are also trades which, for some reason, get delayed and show up later in the ""time and sales"" window. But to answer the question of why someone would want to sell low... the only reason I could think is they desire to drive the price down." This would be a nice Raspberry Pi project for Mathematica, which comes bundled free on the Raspbian OS. You can program it up and leave it running.  It's not expensive and doesn't use much power. A program to monitor stock prices or volume could be written as simply as :-  This checks the volume of trades of Oct 2014 US crude oil futures every 30 seconds and sends an email if the volume jumps by more than 100. The financial data in this example is curated from Yahoo.  If specific data is not available or not updated frequently enough, if you can find an alternative online data source it's usually possible read the data in.  For example, this is apparently real-time data :- {Crude Oil, 92.79, -0.67, -0.71%} After leaving the above program running while writing this the volume of trades has risen like so :-  Edit I just set this running on a Raspberry Pi.  I had to use gmail for the email setup as described in this post: Configuring Mathematica to send email from a notebook.  Anyway, it's working.  Hope I don't get inundated with emails. ;-)