How to diversify IRA portfolio given fund minimum investments and IRA contribution limits?
There are fund of funds,e.g. life cycle funds or target retirement funds, that could cover a lot of these with an initial investment that one could invest into for a few years and then after building up a balance large enough, then it may make sense to switch to having more control. If you have other savings, the diversification occurs across the accounts. e.g. my 401(k) has access to the insanely low .02% fee VIIIX (Vanguard S&P fund) You can bet it's 100% in. My IRAs are the other assets that make the full picture look better allocated.  A new investor has the issue you suggest, although right now, you can deposit $5500 for 2013, and $5500 for 2014, so with $11K available, you can start with $6 or $9K and start with 2 or 3 funds. Or $9K now, but with $500 left over for the '14 deposit, you can deposit $6K in early '15.  The disparity of $3K min/$5500 annual limit is annoying, I agree, but shouldn't be a detriment to your planning. Many mutual fund companies (including Vanguard when I checked many years ago) require smaller minimum investments (often $1000) for IRA and 401k accounts.  Some also allow for smaller investments into their funds for  IRA accounts if you set up an automatic investment plan that contributes  a fixed amount of money each month or each quarter.  On the other hand,  many mutual fund companies charge an annual account maintenance fee ($10? $20? $25? more?) per fund for IRA investments unless the balance in the fund is above a certain amount (often $5K or $10K$).  This fee can be paid in cash or deducted from the IRA investment, and the former option is vastly better. So, diversification into multiple funds while starting out with an IRA is not that great an idea. It is far better to get diversification through investment in an S&P 500 Index fund (VFINX since you won't have access to @JoeTaxpayer's VIIIX) or a Total Market Index fund or, if you prefer, a Target Retirement Fund, and then branch out into other types of mutual funds as your investment grows through future contributions and dividends etc. To answer your question about fund minimums, the IRA account is separate from a taxable investment account, and the minimum rule applies to each separately. But, as noted above, there often are smaller minimums for tax-deferred accounts.
From Vanguard's Best practices for portfolio rebalancing: "There are probably 3-4 questions here.  Diversification - A good index, a low cost S&P fund or ETF can serve you very well. If you add an extended market index or just go with ""Total market"", that might be it for your stock allocation. I've seen people with 5 funds, and it didn't take much analysis to see the overlap was so significant, that the extra 4 funds added little, and 2 of the 5 would have been it. If you diversify by buying more ETFs or funds, be sure to see what they contain.  If you can go back in time, buy Apple, Google, Amazon, etc, and don't sell them. Individual stocks are fun to pick, but unless you put in your homework, are tough to succeed at. You need to be right at the buy side, and again to know if, and when, to sell. I bought Apple, for example, long ago, pre-last few splits. But, using responsible a approach, I sold a bit each time it doubled. Has I kept it all through the splits, I'd have $1M+ instead of the current $200K or so of stock. Can you tell which companies now have that kind of potential for the future?  The S&P has been just about double digit over 60 years. The average managed fund will lag the S&P over time, many will be combined with other funds or just close. Even with huge survivor bias, managed funds can't beat the index over time, on average. Aside from a small portion of stocks I've picked, I'm happy to get S&P less .02% in my 401(k). In aggregate, people actually do far worse due to horrific timing and some odd thing, called emotions." Asset Allocation serves many purposes, not just mitigating risk via a diversification of asset classes, but also allowing you to take a level of risk that is appropriate for a given investor at a given time by how much is allocated to which asset classes. A younger investor with a longer timeframe, may wish to take a lot more risk, investing heavily in equities, and perhaps managed funds that are of the 'aggressive growth' variety, seeking better than market returns. Someone a little older may wish to pull back a bit, especially after a bull market has brought them substantial gains, and begin to 'take money off the table' perhaps by starting to establish some fixed income positions, or pulling back to slightly less risky index,  'value' or 'balanced' funds. An investor who is near or in retirement will generally want even less risk, going to a much more balanced approach with half or more of their investments in fixed income, and the remainder often in income producing 'blue chip' type stocks, or 'income funds'.  This allows them to protect a good amount of their wealth from potential loss at a time when they have to be able to depend on it for a majority of their income. An institution such as Yale has very different concerns, and may always be in a more aggressive 'long term' mode since 'retirement' is not a factor for them.  They are willing to invest mostly in very aggressive ways, using diversification to protect them from one of those choices 'tanking' but still overall taking a pretty high level of risk, much more so than might be appropriate for an individual who will generally need to seek safety and to preserve gains as they get older.  For example look at the PDF that @JLDugger linked, and observe the overall risk level that Yale is taking, and in addition observe the large allocations they make to things like private equity with a 27%+ risk level compared to their very small amount of fixed income with a 10% risk level.  Yale has a very long time horizon and invests in a way that is atypical of the needs and concerns of an individual investor.  They also have as you pointed out, the economy of scale (with something like #17B in assets?) to afford to hire proven experts, and their own internal PHD level experts to watch over the whole thing, all of which very few individual investors have. For either class of investor, diversification, is a means to mitigate risk by not having all your eggs in one basket.  Via having multiple different investments (such as picking multiple individual stocks, or aggressive funds with different approaches, or just an index fund to get multiple stocks) you are protected from being wiped out as might happen if a single choice might fail.  For example imagine what would have happened if you had in 2005 put all your money into a single stock with a company that had been showing record profits  such as Lehman Brothers, and left it there until 2008 when the stock tanked. or even faster collapses such as Enron, etc that all 'looked great' up until shortly after they failed utterly.   Being allocated across multiple asset classes provides some diversification all on it's own, but you can also be diversified within a class. Yale uses the diversification across several asset classes to have lower risk than being invested in a single asset class such as private equity. But their allocation places much more of their funds in high risk classes and much less of their funds in the lowest risk classes such as fixed income. Apply as many deductions as you are legally entitled to. Those are taxes you may never ever pay.  Then turn around and put any more monies above the maximum retirement contributions into a taxable account. But this time invest in tax efficient investments. For example, VTI or SPY will incur very minimal taxes and when you withdraw, it will be at lower tax rate (based on current tax laws). Just as you diversify your investments, you also want to diversify your taxes. I really like keshlam's answer. Your age is also a consideration. If you make your own target fund by matching the allocations of whatever Vanguard offers, I'd suggest re-balancing every year or every other year. But if you're just going to match the allocations of their target fund, you might as well just invest in the target fund itself. Most (not all, just most) target funds do not charge an additional management fee. So you just pay the fees of the underlying funds, same as if you mirrored the target fund yourself. (Check the prospectus to see if an additional fee is charged or not.) You may want to consider a more aggressive approach than the target funds. You can accomplish this by selecting a target fund later than your actual retirement age, or by picking your own allocations. The target funds become more conservative as you approach retirement age, so selecting a later target is a way of moving the risk/reward ratio. (I'm not saying target funds are necessarily the best choice, you should get professional advice, etc etc.) First, you should diversify your portfolio.  If your entire portfolio is in the Roth IRA, then you should eventually diversify that.  However, if you have an IRA and a 401k, then it's perfectly fine for the IRA to be in a single fund.  For example, I used my IRA to buy a riskier REIT that my 401k doesn't support.   Second, if you only have a small amount currently invested, e.g. $5500, it may make sense to put everything in a single fund until you have enough to get past the low balance fees.  It's not uncommon for funds to charge lower fees to someone who has $8000, $10,000, or $12,000 invested.  Note that if you deposit $10,000 and the fund loses money, they'll usually charge you the rate for less than $10,000.  So try to exceed the minimum with a decent cushion.   A balanced fund may make sense as a first fund.  That way they handle the diversification for you.  A targeted fund is a special kind of balanced fund that changes the balance over time.  Some have reported that targeted funds charge higher fees.  Commissions on those higher fees may explain why your bank wants you to buy.   I personally don't like the asset mixes that I've seen from targeted funds.  They often change the stock/bond ratio, which is not really correct.  The stock/bond ratio should stay the same.  It's the securities (stocks and bonds) to monetary equivalents that should change, and that only starting five to ten years before retirement.  Prior to that the only reason to put money into monetary equivalents is to provide time to pick the right securities fund.  Retirees should maintain about a five year cushion in monetary equivalents so as not to be forced to sell into a bad market.   Long term, I'd prefer low-load index funds.  A bond fund and two or three stock funds.  You might want to build your balance first though.  It doesn't really make sense to have a separate fund until you have enough money to get the best fees.  70-75% stocks and 25-30% bonds (should add to 100%, e.g. 73% and 27%).  Balance annually when you make your new deposit. Have a look at: Diversify Portfolio. The site provides various tools all focused on correlation, diversification and portfolio construction. You can scan through every stock and ETF listed on the NASDAQ and NYSE to find any kind of correlation you're looking for. You can also create a portfolio and then analyze all the correlations within it, or search for specific stocks that can be added to the portfolio based on correlation and various other factors. Quick and dirty paper but pretty interesting.. I'm not in Portfolio Management but I probably would have ended up at the modal number as well.   I don't know the subject deeply enough to answer my own question, but is the bias always toward underestimation of variance? Or is that a complex of the way the problem was set up?   Another question I have for those in investment management; Would this impact asset allocation? It depends on how much diversification you think you need and what your mutual fund options are. For instance, picking an index fund already provides a fair amount of diversification, especially if you select a Total Market type of index (readily available from Fidelity and Vanguard, and many other fund families). Are you looking to balance domestic vs. international investments? You may want to add an international index fund to the mix. Feel that a particular sector has tremendous potential? Add a sector fund. This investment mix is up to you (or your investment advisor). However, depending on your Roth IRA mutual fund choices, some of these funds may have minimum investment requirement - $3k to open a fund's account, for instance. In that case, you'd have no choice but to put your entire investment into one fund, and wait for subsequent years where you'd be able to invest in other funds after providing additional contributions and/or reallocation any growth from your initial investment. One thing to look at is whether you have an option of putting some of your contributions into a money market account within the Roth IRA - you can then reallocate funds from that account into another fund after you can meet the minimum investment requirement. However, in my opinion, if you start out by investing in a solid, low-cost index fund from a reputable mutual fund company, you've already picked up most of the diversification you need - a single fund is enough. Oh, ok. You have $3.8m cash to work with in creating a low-risk investment portfolio. All you need to do is pick investment options that stick to the three objectives of the fund. You may assume all the capital is available for immediate investment ($200k out of the $4m is set aside for scholarships so it must stay liquid). Your initial premise (mid-cap and small-cap company stocks have outperformed the market) is partially correct - they have, over many 40 yr periods, provided higher returns than large caps (or bond funds). The important thing to consider here is that risk adjusted, the returns from a diversified portfolio are far more robust - with proper asset allocation you and expect high returns and reduce your risk simultaneously.  Imagine this scenario - you decide to stick to small / mid caps for 10 - 15 yrs and move into a more diversified portfolio then. Had you made that decision during a sustained period of poor small cap performance (late 80s or the 40's) you would have lost a boatload of return, as those were periods were small / mids underperformed the market as a whole, and large caps in particular. As an example, from 1946 to 1958 large caps outperformed small every single year. If 2016 were to be the first year of a similar trend, you've done yourself a major disservice.  Since the dot com crash small /mids have outperformed for sure, pretty much every year - but that doesn't mean that they will continue to do so. The reason asset allocation exists is precisely this - over a 40 yr period, no single asset class outperforms a diversified portfolio.  If you attempt to time the market, even if you do so with a multi-decade time horizon in mind, there a good chance that you will do more poorly. "The way I've implemented essentially ""value averaging"", is to keep a constant ratio between different investment types in my portfolio. Lets say (in a simple example), 25% cash, 25% REIT (real estate), 25% US Stock, 25% Foreign stock. Lets say I deposit a set $1000 per month into this account. If the stock portion goes up, it will look like I need more cash & REIT, so all of that $1000 goes into cash & the REIT portion to get them towards their 25%. I may spend months investing only in cash & the REIT while the stock goes up. Of course if the stock goes down, that $1000 per month goes into the stock accounts. Now you can also balance your account if you'd like, regularly selling stock (or the REIT), and making the account balanced. So if the stock goes down, you'd use the cash & REIT to purchase more stock. If the stock went up, you'd sell the stock, and buy REIT & leave more in cash." No, you can't. The limits are contribution limits, not limits on the value of the investment.  If you contributed $5,500 for 2015, you are done contributing for that tax year. You are free to contribute another $5,500 for 2016. I don't like your strategy.  Don't wait.  Open an investment account today with a low cost providers and put those funds into a low cost investment that represents as much of the market as you can find. I am going to start by assuming you are a really smart person.  With that assumption I am going to assume you can see details and trends and read into the lines.  As a computer programmer I am going to assume you are pretty task oriented, and that you look for optimal solutions. Now I am going to ask you to step back.  You are clearly very good at managing your money, but I believe you are over-thinking your opportunity. Reading your question, you need a starting place (and some managed expectations), so here is your plan: Now that you have a personal retirement account (IRA, Roth IRA, MyRA?) and perhaps a 401(k) (or equivalent) at work, you can start to select which investments go into that account.  I know that was your question, but things you said in your question made me wonder if you had all of that clear in your head. The key point here is don't wait.  You won't be able to time the market; certainly not consistently.  Get in NOW and stay in.  You adjust your investments based on your risk tolerance as you age, and you adjust your investments based on your wealth and needs.  But get in NOW.   Over the course of 40 years you are likely to be working, sometimes the market will be up, and sometimes the market will be down; but keep buying in.  Because every day you are in, you money can grow; and over 40 years the chances that you will grow substantially is pretty high.  No need to wait, start growing today. Things I didn't discuss but are important to you: "When you have multiple assets available and a risk-free asset (cash or borrowing) you will always end up blending them if you have a reasonable objective function.  However, you seem to have constrained yourself to 100% investment.  Combine that with the fact that you are considering only two assets and you can easily have a solution where only one asset is desired in the portfolio.  The fact that you describe the US fund as ""dominating"" the forign fund indicates that this may be the case for you.  Ordinarily diversification benefits the overall portfolio even if one asset ""dominates"" another but it may not in your special case. Notice that these funds are both already highly diversified, so all you are getting is cross-border diversification by getting more than one.  That may be why you are getting the solution you are.  I've seen a lot of suggested allocations that have weights similar to what you are using. Finding an optimal portfolio given a vector of expected returns and a covariance matrix is very easy, with some reliable results.  Fancy models get pretty much the same kinds of answers as simple ones.  However, getting a good covariance matrix is hard and getting a good expected return vector is all but impossible.  Unfortunately portfolio results are very sensitive to these inputs.  For that reason, most of us use portfolio theory to guide our intuition, but seldom do the math for our own portfolio.  In any model you use, your weak link is the expected return and covariance.  More sophisticated models don't usually help produce a more reasonable result. For that reason, your original strategy (80-20) sounds pretty good to me.  Not sure why you are not diversifying outside of equities, but I suppose you have your reasons."