Comparing ETFs following the same index
The key two things to consider when looking at similar/identical ETFs is the typical (or 'indicative') spread, and the trading volume and size of the ETF. Just like regular stocks, thinly traded ETF's often have quite large spreads between buy and sell: in the 1.5-2%+ range in some cases. This is a huge drain if you make a lot of transactions and can easily be a much larger concern than a relatively trivial difference in ongoing charges depending on your exact expected trading frequency. Poor spreads are also generally related to a lack of liquidity, and illiquid assets are usually the first to become heavily disconnected from the underlying in cases where the authorized participants (APs) face issues. In general with stock ETFs that trade very liquid markets this has historically not been much of an issue, as the creation/redemption mechanism on these types of assets is pretty robust: it's consequences on typical spread is much more important for the average retail investor. On point #3, no, this would create an arbitrage which an authorized participant would quickly take advantage of. Worth reading up about the creation and redemption mechanism (here is a good place to start) to understand the exact way this happens in ETFs as it's very key to how they work.
"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. :)" I think you understood much of what I say, in general. Unfortunately, I didn't follow Patches math.  What I gleen from your summary is a 1% match to the 10% invested, but a .8% expense. The ETF VOO has a .05% annual fee, a bit better than SPY.  A quick few calculations show that the 10% bonus does offset a long run of the .75% excess expense compared to external investing. After decades, the 401(k) appears to still be a bit ahead. Not the dramatic delta suggested in the prior answer, but enough to stay with the 401(k) in this situation. The tiny match still makes the difference. Edit - the question you linked to. The 401(k) had no match, and an awful 1.2% annual expense. This combination is deadly for the younger investor. Always an exception to offer - a 25% marginal rate earner close to retiring at 15%. The 401(k) deposit saves him 25, but can soon be withdrawn at 15, it's worth a a few years of that fee to make this happen. For the young person who is planning a quick exit from the company, same deal. @BlackJack does a good answer of addressing the gains and when you are taxed on them and at what kind of rate. Money held in a brokerage account will usually be in a money-market fund, so you would own taxes on the interest it earned.   There is one important consideration that must be understood for capitol Losses.  This is called the Wash Sale Rule.  This rule comes into affect if you sell a stock at a LOSS, and buy shares of the same stock within 30 days (before or after) the sale.  A common tactic used to minimize taxes paid is to 'capture losses' when they occur, since these can be used to offset gains and lower your taxes.  This is normally done by selling a stock in which you have a LOSS, and then either buying another similar stock, or waiting and buying back the stock you sold.   However, if you are intending to buy back the same stock, you must not 'trigger' the Wash Sale Rule or you are forbidden to take the loss. Examples.  Lets presume you own 1000 shares of a stock and it's trading 25% below where you bought it, and you want to capture the loss to use on your taxes. This can be a very important consideration if trading index ETF's  if you have a loss in something like a S&P500 ETF, you would likely incur a wash sale if you sold it and bought a different S&P500 ETF from another company since they are effectively the same thing.  OTOH, if you sold an S&P500 ETF and bought something like a 'viper''total stock market' ETF it should be different enough to not trigger the wash sale rule.  If you are trying to minimize the taxes you pay on stocks, there are basically two rules to follow.  1) When a gain is involved, hold things at least a year before selling, if at all possible.  2) Capture losses when they occur and use to offset gains, but be sure not to trigger the wash sale rule when doing so. Behind the scenes, mutual funds and ETFs are very similar.  Both can vary widely in purpose and policies, which is why understanding the prospectus before investing is so important. Since both mutual funds and ETFs cover a wide range of choices, any discussion of management, assets, or expenses when discussing the differences between the two is inaccurate.  Mutual funds and ETFs can both be either managed or index-based,  high expense or low expense, stock or commodity backed. Method of investing When you invest in a mutual fund, you typically set up an account with the mutual fund company and send your money directly to them.  There is often a minimum initial investment required to open your mutual fund account.  Mutual funds sometimes, but not always, have a load, which is a fee that you pay either when you put money in or take money out. An ETF is a mutual fund that is traded like a stock.  To invest, you need a brokerage account that can buy and sell stocks.  When you invest, you pay a transaction fee, just as you would if you purchase a stock.  There isn't really a minimum investment required as there is with a traditional mutual fund, but you usually need to purchase whole shares of the ETF.  There is inherently no load with ETFs. Tax treatment Mutual funds and ETFs are usually taxed the same.  However, capital gain distributions, which are taxable events that occur while you are holding the investment, are more common with mutual funds than they are with ETFs, due to the way that ETFs are structured.  (See Fidelity: ETF versus mutual funds: Tax efficiency for more details.)  That having been said, in an index fund, capital gain distributions are rare anyway, due to the low turnover of the fund. Conclusion When comparing a mutual fund and ETF with similar objectives and expenses and deciding which to choose, it more often comes down to convenience.  If you already have a brokerage account and you are planning on making a one-time investment, an ETF could be more convenient.  If, on the other hand, you have more than the minimum initial investment required and you also plan on making additional regular monthly investments, a traditional no-load mutual fund account could be more convenient and less expensive. Eh using a benchmark that's designed for Hedge Funds is a little different. I was guessing the other comment was referring to SPX or similar for the 10%. Most people don't understand HF as investment vehicles. They are meant to be market neutral and focused on absolute returns. Yes, you can benchmark them against each other / strategy but most people here seem to think that HFs want to beat the S&amp;P 500. He said he's using MSCI World as a benchmark. MSCI World is not an exchange. The point is the same security listed in different places has different prices, so how do you describe the equity beta of the company to MSCI World if you have multiple and different return streams? This is a real problem to consider and you just dismiss it entirely. After looking at both S&P GSCI Crude Oil Index Excess Return (INDEXSP:SPGSCLP) and CS VS 3x LC ETN NYSEARCA: UWTI they seem to track well (using Google Finance).   I'm not seeing where your statement this ETN loses whether oil is gaining or not holds true.   Both have posted a year-over-year loss. In the past year the Crude Oil index has fallen from a high of 494 on October 6, 2014 to a low of 213 as of today October 5th, 2015.  So of course the UWTI will lose as well. Please also notice that that, as stated in the prospectus for UWTI: The ETNs are intended to be daily trading tools for sophisticated   investors to manage daily trading risks. They are designed t o achieve   their stated investment objectives on a daily basis, but their   performance over different periods of time can differ significantly fr   om their stated daily objectives. The ETNs are riskier than securities   that have intermediate or long-term investment objectives, and may not   be sui table for investors who plan to hold them for a period other   than one day. You might want to look into investing in an ETF for long term investment goals and objectives.  Oil ETF List SeekingAlpha has a section dedicated to Short ETFs as well as others. In there you will find SH, and SDS.  Both of which are inverse to the S&P 500.  Edit: I linked to charts that compare SH and SDS to SPY.