Understanding differences between S&P500 index-tracking ETFs
"Regarding SPY: ""One SPDR unit is valued at approximately 1/10 of the value of the S&P 500. Dividends are distributed quarterly, and are based on the accumulated stock dividends held in trust, less any expenses of the trust.""  (source)  These are depository receipts, not the actual stocks. Regarding IVV: ""The component stocks are weighted according to the total float-adjusted market value of their outstanding shares. The Fund invests in sectors, such as energy, information technology, industrials, financials, consumer staples, healthcare, telecom services, consumer discretionary and materials.""  (more here) VOO is the Vanguard S&P 500 ETF. The tracking error seems pretty small to me.  I went to Google Finance and plotted the percent change for all four on one chart.  They lie pretty much on top of one another.  The actual dollar value of each one doesn't matter nearly as much as the fact that they move up and down almost in lock-step.  There may be a larger difference going farther out, but for three separate financial products, the agreement is still remarkably good." "Back in the olden days, if you wanted to buy the S&P, you had to have a lot of money so you can buy the shares. Then somebody had the bright idea of making a fund that just buys the S&P, and then sells small pieces of it to investor without huge mountains of capital. Enter the ETFs. The guy running the ETF, of course, doesn't do it for free. He skims a little bit of money off the top. This is the ""fee"". The major S&P ETFs all have tiny fees, in the percents of a percent. If you're buying the index, you're probably looking at gains (or losses) to the tune of 5, 10, 20% - unless you're doing something really silly, you wouldn't even notice the fee. As often happens, when one guy starts doing something and making money, there will immediately be copycats. So now we have competing ETFs all providing the same service. You are technically a competitor as well, since you could compete with all these funds by just buying a basket of shares yourself, thereby running your own private fund for yourself. The reason this stuff even started was that people said, ""well why bother with mutual funds when they charge such huge fees and still don't beat the index anyway"", so the index ETFs are supposed to be a low cost alternative to mutual funds. Thus one thing ETFs compete on is fees: You can see how VOO has lower fees than SPY and IVV, in keeping with Vanguard's philosophy of minimal management (and management fees). Incidentally, if you buy the shares directly, you wouldn't charge yourself fees, but you would have to pay commissions on each stock and it would destroy you - another benefit of the ETFs. Moreover, these ETFs claim they track the index, but of course there is no real way to peg an asset to another. So they ensure tracking by keeping a carefully curated portfolio. Of course nobody is perfect, and there's tracking error. You can in theory compare the ETFs in this respect and buy the one with the least tracking error. However they all basically track very closely, again the error is fractions of the percent, if it is a legitimate concern in your books then you're not doing index investing right. The actual prices of each fund may vary, but the price hardly matters - the key metric is does it go up 20% when the index goes up 20%? And they all do. So what do you compare them on? Well, typically companies offer people perks to attract them to their own product. If you are a Fidelity customer, and you buy IVV, they will waive your commission if you hold it for a month. I believe Vanguard will also sell VOO for free. But for instance Fidelity will take commission from VOO trades and vice versa. So, this would be your main factor. Though, then again, you can just make an account on Robinhood and they're all commission free. A second factor is reliability of the operator. Frankly, I doubt any of these operators are at all untrustworthy, and you'd be buying your own broker's ETF anyway, and presumably you already went with the most trustworthy broker. Besides that, like I said, there's trivial matters like fees and tracking error, but you might as well just flip a coin. It doesn't really matter."
Exchange-traded funds are bought and sold like stocks so you'd be able to place stop orders on them just like you could for individual stocks. For example, SPY would be the ticker for an S & P 500 ETF known as a SPDR. Open-end mutual funds don't have stop orders because of how the buying and selling is done which is on unknown prices and often in fractional shares. For example, the Vanguard 500 Index Investor shares(VFINX) would be an example of an S & P 500 tracker here. that's just it, though - they are splitting up the 1%! and in most cases, especially vanguard, they are splitting up far less.  ETFs don't have 12b-1 fees. explaining why you're experiencing different returns for ETFs will almost certainly involve something other than their expense. again, this is especially true for vanguard. they have the cheapest ETFs around (though i think schwab beats them on a few now).  i can only guess at the full compensation structure. betterment likely earns money on cash reserves and  securities hypothecation (i guess?). they also charge a small fee from what i understand. finance is very slim these days.  i guess i'm wondering what your ultimate question is. if it's the inter corporate compensation structure, above is my best guess. if it's about performance, then we need to compare the ETFs you are looking at. if it's about the fees on funds, i think we covered that!  as an advisor, it's my experience that very specific inquiries about fees have a deeper concern. people hear a lot about being overcharged so cost is a very standard place for clients to initially look when trying to compare performance of portfolios or securities. "Buy the ETF with ticker ""SPY"".  This will give you exposure to exactly the S&P 500 stocks,  This is similar to the mutual fund suggestion by Ben Miller, except that the ETF has several advantages over mutual funds, especially as regards taxes.  You can find information on the difference between ETF and mutual fund in other questions on this site or by searching the web." The S&P500 is an index, not an investment by itself.  The index lists a large number of stocks, and the value of the index is the price of all the stocks added together. If you want to make an investment that tracks the S&P500, you could buy some shares of each stock in the index, in the same proportions as the index.  This, however, is impractical for just about everyone. Index mutual funds provide an easy way to make this investment.  SPY is an ETF (exchange-traded mutual fund) that does the same thing. An index CFD (contract for difference) is not the same as an index mutual fund.  There are a number of differences between investing in a security fund and investing in a CFD, and CFDs are not available everywhere. great example of levered tracking error is any 2x/3x VIX etf. during periods of high volatility (like last week) you will be able to realize much higher returns on the underlying index as the levered and inverse ETFs are unable to replicate their intended performance using market securities.  it is not uncommon to see the VIX up ~30% with levered ETFs only netting ~10-12% as opposed to the intended 60 or 90%, for example I think that assuming that you're not looking to trade the fund, an index Mutual Fund is a better overall value than an ETF. The cost difference is negligible, and the ability to dollar-cost average future contributions with no transaction costs. You also have to be careful with ETFs; the spreads are wide on a low-volume fund and some ETFs are going more exotic things that can burn a novice investor. Track two similar funds (say Vanguard Total Stock Market: VTSMX and Vanguard Total Stock Market ETF: VTI), you'll see that they track similarly.  If you are a more sophisticated investor, ETFs give you the ability to use options to hedge against declines in value without having to incur capital gains from the sale of the fund. (ie. 20 years from now, can use puts to make up for short-term losses instead of selling shares to avoid losses)  For most retail investors, I think you really need to justify using ETFs versus mutual funds. If anything, the limitations of mutual funds (no intra-day trading, no options, etc) discourage speculative behavior that is ultimately not in your best interest. EDIT: Since this answer was written, many brokers have begun offering a suite of ETFs with no transaction fees. That may push the cost equation over to support Index ETFs over Index Mutual Funds, particularly if it's a big ETF with narrow spreads.. One difference is the bid/ask spread will cost you more in a lower cost stock than a higher cost one. Say you have two highly liquid stocks with tiny spreads: If you wanted to buy say $2,000 of stock: Now imagine these are almost identical ETFs tracking the S&P 500 index and extrapolate this to a trade of $2,000,000 and you can see there's some cost savings in the higher priced stock. As a practical example, recently a popular S&P 500 ETF (Vanguard's VOO) did a reverse split to help investors minimize this oft-missed cost. You can check the website for the company that manages the fund. For example, take the iShares Nasdaq Biotechnology ETF (IBB). iShares publishes the complete list of the fund's holdings on their website. This information isn't always easy to find or available, but it's a place to start. For some index funds, you should just be able to look up the index the fund is trying to match. This won't be perfect (take Vanguard's S&P 500 ETF (VOO); the fund holds 503 stocks, while the S&P 500 index is comprised of exactly 500), but once again, it's a place to start. A few more points to keep in mind. Remember that many ETF's, including equity ETF's, will hold a small portion of their assets in cash or cash-equivalent instruments to assist with rebalancing. For index funds, this may not be reflected in the index itself, and it may not show up in the list of holdings. VOO is an example of this. However, that information is usually available in the fund's prospectus or the fund's site. Also, I doubt that many stock ETF's, at least index funds, change their asset allocations all that frequently. The amounts may change slightly, but depending on the size of their holdings in a given stock, it's unlikely that the fund's manager would drop it entirely. Index funds: Some of the funds listed by US SIF are index funds. ETFs: ETFdb has a list, though it's pretty short at the moment. In your other question about these funds you quoted two very different yields for them. That pretty clearly says they are NOT tracking the same index. So, why or why should I not invest in the cheaper index fund? They are both same, one is not cheaper than other. You get something that is worth $1000.  To give a simple illustration; There is an item for $100, Vanguard creates 10 Units out of this so price per unit is $10. Schwab creates 25 units out of this, so the per unit price is $4. Now if you are looking at investing $20; with Vanguard you would get 2 units, with Schwab you would get 5 units. This does not mean one is cheaper than other. Both are at the same value of $20.   The Factors you need to consider are; Related question What differentiates index funds and ETFs? "Following comments to your question here, you posted a separate question about why SPY, SPX, and the options contract don't move perfectly together.  That's here Why don't SPY, SPX, and the e-mini s&p 500 track perfectly with each other? I provided an answer to that question and will build on it to answer what I think you're asking on this question.  Specifically, I explained what it means that these are ""all based on the S&P.""  Each is a different entity, and different market forces keep them aligned.  I think talking about ""technicals"" on options contracts is going to be too confusing since they are really a very different beast based on forward pricing models, so, for this question, I'll focus on only SPY and SPX. As in my other answer, it's only through specific market forces (the creation / redemption mechanism that I described in my other answer), that they track at all.  There's nothing automatic about this and it has nothing to do with some issuer of SPY actually holding stock in the companies that comprise the SPX index. (That's not to say that the company does or doesn't hold, just that this doesn't drive the prices.)  What ever technical signals you're tracking, will reflect all of the market forces at play.  For SPX (the index), that means some aggregate behavior of the component companies, computed in a ""mathematically pure"" way.  For SPY (the ETF), that means (a) the behavior of SPX and (b) the behavior of the ETF as it trades on the market, and (c) the action of the authorized participants.  These are simply different things. Which one is ""right""?  That depends on what you want to do.  In theory you might be able to do some analysis of technical signals on SPY and SPX and, for example, use that to make money on the way that they fail to track each other.  If you figure out how to do that, though, don't post it here.  Send it to me directly. :)" "At the bottom of Yahoo! Finance's S & P 500 quote Quotes are real-time for NASDAQ, NYSE, and NYSE MKT. See also delay   times for other exchanges. 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Yet, what is generally meant when the label ""ETF"" is used (despite CEFs also being both ""exchange-traded"" and ""funds"") are those securities which are not just exchange-traded, and funds, but also typically have two specific characteristics: (a) that they are based on some published index, and (b) that a mechanism exists for shares to be created or redeemed by large market participants. These characteristics facilitate efficient pricing through arbitrage. Essentially, when large market participants notice the price of an ETF diverging from the value of the shares held by the fund, new units of the ETF can get created or redeemed in bulk. The divergence quickly narrows as these participants buy or sell ETF units to capture the difference. So, the persistent premium (sometimes dear) or discount (sometimes deep) one can easily witness in the CEF universe tend not to occur with the typical ETF. Much of the time, prices for ETFs will tend to be very close to their net asset value. However, it isn't always the case, so proceed with some caution anyway. Both CEF and ETF providers generally publish information about their funds online. You will want to find out what is the underlying Net Asset Value (NAV) per share, and then you can determine if the market price trades at a premium or a discount to NAV. Assuming little difference in an ETF's price vs. its NAV, the more interesting question to ask about an ETF then becomes whether the NAV itself is a bargain, or not. That means you'll need to be more concerned with what stocks are in the index the fund tracks, and whether those stocks are a bargain, or not, at their current prices. i.e. The ETF is a basket, so look at each thing in the basket. Of course, most people buy ETFs because they don't want to do this kind of analysis and are happy with market average returns. Even so, sector-based ETFs are often used by traders to buy (or sell) entire sectors that may be undervalued (or overvalued)." If you just want to track an index, then ETFs are, generally speaking, the better way.