What type of low-cost stock index exchange-traded fund (ETF) would give the best long-term total return?
Small cap and mid cap shares tend to outperform large cap shares in a bull market, but they tend to underperform large cap shares in a bear market. Since the stock markets tend to go up in the long term, this suggests that a low cost small and mid cap index ETF should offer the best long term returns.   Having said that, we are currently in a mature bull market having experienced over seven years without encountering a bear market.  If a bearish outlook is something you worry about, then perhaps a broad market index, which will be heavily weighted towards large cap shares, may be a better choice for you at this time, with an eye toward switching to small and mid cap indices during the next bear market.
"You mentioned three concepts: (1) trading (2) diversification (3) buy and hold.   Trading with any frequency is for people who want to manage their investments as a hobby or profession.  You do not seem to be in that category.  Diversification is a critical element of any investment strategy.  No matter what you do, you should be diversified.  All the way would be best (this means owning at least some of every asset out there).  The usual way to do this is to own a mutual or index fund.  Or several.  These funds own hundreds or thousands of stocks, so that buying the fund instantly diversifies you. Buy and hold is the only reasonable approach to a portfolio for someone who is not interested in spending a lot of time managing it.  There's no reason to think a buy-and-hold portfolio will underperform a typical traded portfolio, nor that the gains will come later.  It's the assets in the portfolio that determine how aggressive/risky it is, not the frequency with which it is traded. This isn't really a site for specific recommendations, but I'll provide a quick idea:  Buy a couple of index funds that cover the whole universe of investments.  Index funds have low expenses and are the cheapest/easiest way to diversify.  Buy a ""total stock market"" fund and a ""total bond fund"" in a ratio that you like.  If you want, also buy an ""international fund.""  If you want specific tickers and ratios, another forum would be better(or just ask your broker or 401(k) provider).  The bogleheads forum is one that I respect where people are very happy to give and debate specific recommendations. At the end of the day, responsibly managing your investment portfolio is not rocket science and shouldn't occupy a lot of time or worry.  Just choose a few funds with low expenses that cover all the assets you are really interested in, put your money in them in a reasonable-ish ratio (no one knows that the best ratio is) and then forget about it." "My original plan was to wait for the next economic downturn and invest   in index funds. These funds have historically yielded 6-7% annually   when entered at any given time, but maybe around 8-9% annually when   entered during a recession. These numbers have been adjusted for   inflation. Questions or comments on this strategy? Educate yourself as index funds are merely a strategy that could be applied to various asset classes such as US Large-cap value stocks, Emerging Market stocks, Real Estate Investment Trusts, US Health Care stocks, Short-term bonds, and many other possibilities. Could you be more specific about which funds you meant as there is some great work by Fama and French on the returns of various asset classes over time. What about a Roth IRA? Mutual fund? Roth IRA is a type of account and not an investment in itself, so while I think it is a good idea to have Roth IRA, I would highly advise researching the ins and outs of this before assuming you can invest in one. You do realize that index funds are just a special type of mutual fund, right? It is also worth noting that there are a few kinds of mutual funds: Open-end, exchange-traded and closed-end. Which kind did you mean? What should I do with my money until the market hits another   recession? Economies have recessions, markets have ups and downs. I'd highly consider forming a real strategy rather than think, ""Oh let's toss it into an index fund until I need the money,"" as that seems like a recipe for disaster. Figure out what long-term financial goals do you have in mind, how OK are you with risk as if the market goes down for more than a few years straight, are you OK with seeing those savings be cut in half or worse?" "An Exchange-Traded Fund (ETF) is a special type of mutual fund that is traded on the stock exchange like a stock.  To invest, you buy it through a stock broker, just as you would if you were buying an individual stock. When looking at a mutual fund based in the U.S., the easiest way to tell whether or not it is an ETF is by looking at the ticker symbol.  Traditional mutual funds have ticker symbols that end in ""X"", and ETFs have ticker symbols that do not end in ""X"".   The JPMorgan Emerging Markets Equity Fund, with ticker symbol JFAMX, is a traditional mutual fund, not an ETF.  JPMorgan does have ETFs; the JPMorgan Diversified Return Emerging Markets Equity ETF, with ticker symbol JPEM, is an example.  This ETF invests in similar stocks as JFAMX; however, because it is an index-based fund instead of an actively managed fund, it has lower fees. If you aren't sure about the ticker symbol, the advertising/prospectus of any ETF should clearly state that it is an ETF.  (In the example of JPEM above, they put ""ETF"" right in the fund name.)  If you don't see ETF mentioned, it is most likely a traditional mutual fund. Another way to tell is by looking at the ""investment minimums"" of the fund.  JFAMX has a minimum initial investment of $1000.  ETFs, however, do not have an investment minimum listed; because it is traded like a stock, you simply buy whole shares at whatever the current share price is.  So if you look at the ""Fees and Investment Minimums"" section of the JPEM page, you'll see the fees listed, but not any investment minimums." "Index funds can be a very good way to get into the stock market. It's a lot easier, and cheaper, to buy a few shares of an index fund than it is to buy a few shares in hundreds of different companies. An index fund will also generally charge lower fees than an ""actively managed"" mutual fund, where the manager tries to pick which stocks to invest for you. While the actively managed fund might give you better returns (by investing in good companies instead of every company in the index) that doesn't always work out, and the fees can eat away at that advantage. (Stocks, on average, are expected to yield an annual return of 4%, after inflation. Consider that when you see an expense ratio of 1%. Index funds should charge you more like 0.1%-0.3% or so, possibly more if it's an exotic index.) The question is what sort of index you're going to invest in. The Standard and Poor's 500 (S&P 500) is a major index, and if you see someone talking about the performance of a mutual fund or investment strategy, there's a good chance they'll compare it to the return of the S&P 500. Moreover, there are a variety of index funds and exchange-traded funds that offer very good expense ratios (e.g. Vanguard's ETF charges ~0.06%, very cheap!). You can also find some funds which try to get you exposure to the entire world stock market, e.g. Vanguard Total World Stock ETF, NYSE:VT). An index fund is probably the ideal way to start a portfolio - easy, and you get a lot of diversification. Later, when you have more money available, you can consider adding individual stocks or investing in specific sectors or regions. (Someone else suggested Brazil/Russia/Indo-China, or BRICs - having some money invested in that region isn't necessarily a bad idea, but putting all or most of your money in that region would be. If BRICs are more of your portfolio then they are of the world economy, your portfolio isn't balanced. Also, while these countries are experiencing a lot of economic growth, that doesn't always mean that the companies that you own stock in are the ones which will benefit; small businesses and new ventures may make up a significant part of that growth.) Bond funds are useful when you want to diversify your portfolio so that it's not all stocks. There's a bunch of portfolio theory built around asset allocation strategies. The idea is that you should try to maintain a target mix of assets, whatever the market's doing. The basic simplified guideline about investing for retirement says that your portfolio should have (your age)% in bonds (e.g. a 30-year-old should have 30% in bonds, a 50-year-old 50%.) This helps maintain a balance between the volatility of your portfolio (the stock market's ups and downs) and the rate of return: you want to earn money when you can, but when it's almost time to spend it, you don't want a sudden stock market crash to wipe it all out. Bonds help preserve that value (but don't have as nice of a return). The other idea behind asset allocation is that if the market changes - e.g. your stocks go up a lot while your bonds stagnate - you rebalance and buy more bonds. If the stock market subsequently crashes, you move some of your bond money back into stocks. This basically means that you buy low and sell high, just by maintaining your asset allocation. This is generally more reliable than trying to ""time the market"" and move into an asset class before it goes up (and move out before it goes down). Market-timing is just speculation. You get better returns if you guess right, but you get worse returns if you guess wrong. Commodity funds are useful as another way to diversify your portfolio, and can serve as a little bit of protection in case of crisis or inflation. You can buy gold, silver, platinum and palladium ETFs on the stock exchanges. Having a small amount of money in these funds isn't a bad idea, but commodities can be subject to violent price swings! Moreover, a bar of gold doesn't really earn any money (and owning a share of a precious-metals ETF will incur administrative, storage, and insurance costs to boot). A well-run business does earn money. Assuming you're saving for the long haul (retirement or something several decades off) my suggestion for you would be to start by investing most of your money* in index funds to match the total world stock market (with something like the aforementioned NYSE:VT, for instance), a small portion in bonds, and a smaller portion in commodity funds. (For all the negative stuff I've said about market-timing, it's pretty clear that the bond market is very expensive right now, and so are the commodities!) Then, as you do additional research and determine what sort investments are right for you, add new investment money in the places that you think are appropriate - stock funds, bond funds, commodity funds, individual stocks, sector-specific funds, actively managed mutual funds, et cetera - and try to maintain a reasonable asset allocation. Have fun. *(Most of your investment money. You should have a separate fund for emergencies, and don't invest money in stocks if you know you're going need it within the next few years)." and seems to do better than the S&P 500 too. No, that's not true. In fact, this fund is somewhere between S&P500 and the NASDAQ Composite indexes wrt to performance. From my experience (I have it too), it seems to fall almost in the middle between SPY and QQQ in daily moves. So it does provide diversification, but you're basically diversifying between various indexes. The cost is the higher expense ratios (compare VTI to VOO). Longing the short ETF will give you better returns than shorting the long etf.  The reason is that as the price gets the smaller the absolute price change gets a lot smaller. So you would rather have upward price exposure than downward.  A good case is SPXU and UPRO absolutely $SPY ETF is the way to go if your point of comparison is the S&P and you want to do low maintenance. Index funds are well-known to give the best long-term investment. Are they? Maybe not all the time! If you had invested in an index fund tracking the S&P500 at the start of 2000 you would still be behind in terms of capital appreciation when taking inflation into considerations. Your only returns in 13.5 years would have been any dividends you may have received. See the monthly chart of the S&P500 below.  Diversification can be good for your overall returns, but diversification simply for diversification sake is as you said, a way of reducing your overall returns in order of smoothing out your equity curve. After looking up indexes for various countries the only one that had made decent returns over a 13.5 year period was the Indian BSE 30 index, almost 400% over 13.5 years, although it also has gone nowhere since the end of 2007 (5.5 years). See monthly chart below.  So investing internationally (especially in developing countries when developed nations are stagnating) can improve your returns, but I would learn about the various international markets first before plunging straight in. Regarding investing in an Index fund vs direct investment in a select group of shares, I did a search on the US markets with the following criteria on the 3rd January 2000:  If the resulting top 10 from the search were bought on 3rd January 2000 and held up until the close of the market on the 19th June 2013, the results would be as per the table below:  The result, almost 250% return in 13.5 years compared to almost no return if you had invested into the whole S&P 500 Index. Note, this table lists only the top ten from the search without screening through the charts, and no risk management was applied (if risk management was applied the 4 losses of 40%+ would have been limited to a maximum of 20%, but possibly much smaller losses or even for gains, as they might have gone into positive territory before coming back down - as I have not looked at any of the charts I cannot confirm this). This is one simple example how selecting good shares can result in much better returns than investing into a whole Index, as you are not pulled down by the bad stocks.