Optimal Asset Allocation
Generally a diversified portfolio will give you a better overall return --a couple of factors that may address what you are looking at - 1) Correlation - The correlation between your two funds is still very high -- it's partially a function of how global economies are related and many companies are now multi-national.  It may help if you diversified into other types of products.   2) Diversification - Following up from before, you may want to also look into diversifying into some bonds, commodities, reits, etc.  They will have a much smaller correlation with a total domestic stock fund. 3) Returns - I'm not sure if by dominate you mean that it has better overall returns, but the point of diversification is to to get you the highest returns.  It's really the ability to limit the risk for the returns - this really translates to limiting the volatility.  This may mean that overall your max returns could be lower-- ie: maybe VTSAX  gives potential average returns between 3%-11%.  A diversified portfolio may give you potential average returns of 5%-9%.  A similar article debating the merits of 'smart beta ETFs' if you are curious. Hope that helps. "There are some good answers about the benefits of diversification, but I'm going to go into what is going on mathematically with what you are attempting. I was always under the assumption that as long as two securities are less than perfectly correlated (i.e. 1), that the standard deviation/risk would be less than if I had put 100% into either of the securities. While there does exist a minimum variance portfolio that is a combination of the two with lower vol than 100% of either individually, this portfolio is not necessarily the portfolio with highest utility under your metric.  Your metric includes returns not just volatility/variance so the different returns bias the result away from the min-vol portfolio. Using the utility function: E[x] - .5*A*sig^2 results in the highest utility of 100% VTSAX. So here the Sharpe ratio (risk adjusted return) of the U.S. portfolio is so much higher than the international portfolio over the period tracked that the loss of returns from adding more international stocks outweigh the lower risk that you would get from both just adding the lower vol international stocks and the diversification effects from having a correlation less than one. The key point in the above is ""over the period tracked"".  When you do this type of analysis you implicitly assume that the returns/risk observed in the past will be similar to the returns/risk in the future.   Certainly, if you had invested 100% in the U.S. recently you would have done better than investing in a mix of US/Intl.  However, while the risk and correlations of assets can be (somewhat) stable over time relative returns can vary wildly! This uncertainty of future returns is why most people use a diversified portfolio of assets.  What is the exact right amount is a very hard question though." "There are a couple of reasons to diversify your assets. First, since we cannot predict which of our investments will perform best, we want to ""cast our net"" broadly enough to have something invested in what's going to be performing well. Second, diversification isn't intended to provide the highest returns, but rather it is used to soften the effects of market volatility. By softening the downsides and lowering the overall volatility among our assets, returns are more consistent.  If a model does not address future downside risk it is only telling you part of the story. (Past performance does not guarantee... you get the picture)" "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."
"Over on Quantitative Finance Stack Exchange, I asked and answered a more technical and broader version of this question, Should the average investor hold commodities as part of a broadly diversified portfolio?  In short, I believe the answer to your question is that gold is neither an investment nor a hedge against inflation. Although many studies claim that commodities (such as gold) do offer some diversification benefit, the most credible academic study I have seen to date, Should Investors Include Commodities in Their Portfolios After All? New Evidence, shows that a mean-variance investor would not want to allocate any of their portfolio to commodities (this would include gold, presumably). Nevertheless, many asset managers, such as PIMCO, offer funds that are marketed as ""real return"" or ""inflation-managed"" and include commodities (including gold) in their portfolios.  PIMCO has also commissioned some research, Strategic Asset Allocation and Commodities, claiming that holding some commodities offers both diversification and inflation hedging benefits." Overall I think your idea is sound. The key here is to  choose that 401k provider wisely and have a specific asset allocation plan (like Joe mentioned) Summary of this approach: Pluses:  Minuses: I'd consider Vanguard for simple, no frills investing. If you're looking to get into choosing stocks, check out the Motley Fool. "JoeTaxpayer's advice is solid - reallocating to your target asset allocation is the right move.  You should have an Investor Policy Statement (IPS) that maps out your financial objectives, risk tolerance, liquidity constraints, etc.  From the IPS, you can determine your target asset allocation and rebalance accordingly.  A few more comments: It sounds like 100% of your 401k is in US stocks.  You might have other accounts that make your overall portfolio globally diversified, but if not, you want to make sure to set a target asset allocation for a global portfolio.   Your statement ""If this were in my brokerage account I'd probably cash out some of the profits and hold onto it and buy more shares as the market eventually comes back down. But this being a 401k which has semi-monthly deposits from my paycheck, do I just leave it?"" is a bit counterintuitive.  If you are going to try to time the market (a very hard task), it is better to use a retirement account, so you don't have to realize capital gains.  Timing the market is probably a bad idea, but if you engage in market timing, it is probably better to use a retirement account than a brokerage account. If you would like to tilt your asset allocation based on the market valuation, I recommend researching Shiller's Cyclically Adjusted Price to Earnings ratio." There many asset allocation strategies to chose from that beat lifestyle funds. For example: Relative Strength Asset Allocation keeps your money in Stocks when stocks perform well, bonds when they outperform stocks, and cash when both bonds and stocks are under-performing.   The re-allocation happens on a monthly basis. What explains the most of the future returns of a portfolio is the allocation between asset classes. In the long term, stock investments are almost certain to return more than any other kinds of investments. For 40+ years, I would choose a portfolio of 100% stocks. How to construct the portfolio, then? Diversification is the key. You should diversify in time (don't put a large sum of money into your stock portfolio immediately; if you have a large sum to invest, spread it around several years). You should diversify based on company size (invest in both large and small companies). You should also diversify internationally (don't invest in just US companies). If you prefer to pick individual stocks, 20 very carefully selected stocks may provide enough diversification if you keep diversification in mind during stock picking. However, careful stock picking cannot be expected to yield excess returns, and if you pick stocks manually, you need to rebalance your portfolio occasionally. Thus, if you're lazy, I would recommend a mutual fund, or many mutual funds if you have difficulty finding a low-cost one that is internationally diversified. The most important consideration is the cost. You cannot expect careful fund selection to yield excess returns before expenses. However, the expenses are certain costs, so prefer low-cost funds. Almost always this means picking index funds. Avoid funds that have a small number of stocks, because they typically invest only in the largest companies, which means you fail to get diversification in company size. So, instead of Euro STOXX 50, select STOXX 600 when investing to the European market. ETFs may have lower costs than traditional mutual funds, so keep ETFs in mind when selecting the mutual funds in which to invest. For international diversification, do not forget emerging markets. It is not excessive to invest e.g. 20% to emerging markets. Emerging markets have a higher risk but they also have a higher return. A portfolio that does not include emerging markets is not in my opinion well diversified. When getting close to retirement age, I would consider increasing the percentage of bonds in the portfolio. This should be done primarily by putting additional money to bonds instead of selling existing investments to avoid additional taxes (not sure if this applies to other taxation systems than the Finnish one). Bond investments are best made though low-cost mutual funds as well. Keep bond investments in your local currency and risk-free assets (i.e. select US government bonds). Whatever you do, remember that historical return is no guarantee of future return. Actually, the opposite may be true: there is a mean reversion law. If a particular investment has returned well in the past, it often means its price has gone up, making it more likely that the price goes down in the future. So don't select a fund based on its historical return; instead, select a fund based on low costs. However, I'm 99% certain that over a period of 40 years, stocks will return better than other investments. In addition to fund costs, taxes are the other certain thing that will be deducted from your returns. Research what options you have to reduce the taxes you need to pay. 401-K was explained in another answer; this may be a good option. Some things recommended in other answers that I would avoid: No, inaction is not always the rational choice in your scenario. To give an extreme example as proof: Let's say that you have $1,000. The expected value of inaction is $0 - you will end up with the same amount (minus inflation, but we can ignore that for this exercise). If your only other option is an investment which has a 75% chance of losing all of your money, and a 25% chance of doubling your money, then your expected value is ((75% * -$1,000)+ (25% * $1,000)) = -$500. In that case your best option is obviously inaction. However, let's say that you have a 75% chance of losing all of your money, but a 25% chance of making $1,000,000 on your investment. In that case, the expected value of investing is ((75% * -$1,000)+ (25% * $1,000,000)) = $249,250. This means that the rational thing is to make the investment. Basically, the 25% chance of making $1M is worth the 75% chance of losing everything. "First, congratulations on choosing to invest in low cost passively managed plans. If you choose any one of these options and stick with it, you will already be well ahead of most individual investors. Almost all plans will allow you to re-balance between asset classes. With some companies, sales agents will encourage you to sell your overweighted assets and buy underweighted assets as this generates brokerage commissions for them, but when you only need to make minor adjustments, you can simply change the allocation of the new money going into your account until you are back to your target weights. Most plans will let you do this for free, and in general, you will only need to do this every few years at most. I don't see much reason for you to be in the Target funds. The main feature of these plans is that they gradually shift you to a more conservative asset allocation over time, and are designed to prevent people who are close to retirement from being too aggressive and risking a major loss just before retirement. It's very likely that at your age, most plans will have very similar recommendations for your allocation, with equities at 80% or more, and this is unlikely to change for the next few decades. The main benefits of betterment seems to be simplicity and ease of use, but there is one concern I would have for you with betterment. Precisely because it is so easy to tweak your allocation, I'm concerned that you might hurt your long-term results by reacting to short-term market conditions: I know I said I wanted a hands off account, but what if the stock market crashes and I want to allocate more to bonds??? One of the biggest reasons that stock returns are better than bond returns on average is that you are being paid to accept additional risk, and living with significant ups and downs is part of what it means to be in the stock market. If you are tempted to take money out of an asset class when it has been ""losing/feels dangerous"" and put more in when it is ""winning/feels safe"", my concerns is that you will end up buying high and selling low. I'd recommend taking a look at this article on the emotional cycle of investing. My point is simply that it's very likely that if you are moving money in and out of stocks based on volatility, you're much less likely to get the full market return over the long term, and might be better off putting more weight in asset classes with lower volatility. Either way, I'd recommend taking one or more risk tolerance assessments online and making sure you're committed to sticking with a long-term plan that doesn't involve more risk than you can really live with. I tend to lean toward Vanguard Life Strategy simply because Vanguard as a company has been around longer, but betterment does seem very accessible to a new investor. Best of luck with your decision!" Basically, diversifying narrows the spread of possible results, raising  the center of the returns bell-curve by reducing the likelihood of extreme results at either the high or low end.  It's largely a matter of basic statistics. Bet double-or-nothing on a single coin flip, and those are the only possible results, and your odds of a disaster (losing most or all of the money) are 50%. Bet half of it on each of two coin flips, and your odds of losing are reduced to 25% at the cost of reducing your odds of winning to 25%, with 50% odds that you retain your money and can try the game again. Three coins divides the space further; the extremes are reduced to 12.5% each, with the middle being most likely. If that was all there was, this would be a zero-sum game and pure gambling. But the stock market is actually positive-sum, since companies are delivering part of their profits to their stockholder owners. This moves the center of the bell curve up a bit from break-even, historically to about +8%. This is why index funds produce a profit with very little active decision; they treat the variation as mostly random (which seems to work statistically) and just try to capture average results of a (hopefully) slightly above-average bucket of stocks and/or bonds. This approach is boring. It will never double your money overnight. On the other hand, it will never wipe you out overnight. If you have patience and are willing to let compound interest work for you, and trust that most market swings regress to the mean in the long run, it quietly builds your savings while not driving you crazy worrying about it. If all you are looking for is better return than the banks, and you have a reasonable amount of time before you need to pull the funds out, it's one of the more reliably predictable risk/reward trade-off points. You may want to refine this by biasing the mix of what you're holding. The simplest adjustment is how much you keep in each of several major investment categories. Large cap stocks, small cap stocks, bonds, and real estate (in the form of REITs) each have different baseline risk/return curves, and move in different ways in response to news, so maintaining a selected ratio between these buckets and adding the resulting curves together is one simple way to make fairly predictable adjustments to the width (and centerline) of the total bell curve. If you think you can do better than this, go for it. But index funds have been outperforming professionally managed funds (after the management fees are accounted for), and unless you are interested in spending a lot of time researching and playing with your money the odds of your doing much better aren't great unless you're willing to risk doing much worse. For me, boring is good. I want my savings to work for me rather than the other way around, and I don't consider the market at all interesting as a game. Others will feel differently.