What is the daily rebalanced leverage ratio that is ideal for the S&P 500 based on past performance?
"The reason that UltraLong funds and the like are bad isn't because of the leverage ratio. It's because they're compounded daily, and the product of all the doubled daily returns is not mathematically equivalent to the double the long-term return. I'd consider providing big fancy equations using uppercase pi as the 'product of elements in a sequence' operator and other calculus fanciness, but that would be overkill, I don't think I can do TeX here, and I don't know the relevant TeX anyway. Anyway. From the economics theory perspective, the ideal leverage ratio is 1X - that is, unlevered, straight investment. Consider: Using leverage costs money. You know that, surely. If someone could borrow money at N% and invest at an expected N+X%, where X > 0, then they would. They would borrow all the money they could and buy all the S&P500 they could. But when they bought all that S&P500, they'd eventually run out of people who were willing to sell it for that cheap. That would mean the excess return would be smaller. Eventually you'd get to a point where the excess return is... zero? .... well, no, empirically, we can see that it's definitely not zero, and that in the real world that stocks do return more than bonds. Why?  Because stocks are riskier than bonds. The difference in expected return between an index like the S&P500 and a US Treasury bond is due to the relative riskiness of the S&P500, which isn't guaranteed by the US Government to return your principal. Any money that you make off of leverage comes from assuming some sort of a risk. Now, assuming risk can be a profitable thing to do, but there are also a lot of people out there with higher risk tolerance than you, like insurance companies and billionaires, so the market isn't exactly short of people willing to take risks, and you shouldn't expect the returns of ""assuming risk"" in the general case to be qualitatively awesome. Now, it's true that investing in an unlevered fashion is risky also. But that's not an excuse to go leveraged anyway; it's a reason to hold back. In fact, regular stocks are sufficiently risky that most people probably shouldn't be holding a 100% stock portfolio. They should be tempering that risk with bonds, instead, and increasing the size of their bond holdings over time. The appropriate time to use leverage is when you have information which limits your risk. You have done research, and have reason to believe that you understand the future of an individual stock/index better than the rest of the stock market does. You calculate that the potential for achieving returns with leverage outweighs the risks. Then you dump your money into the leveraged position. (In exchange for this, the market receives information about anticipated future returns of this instrument, because of the price movement which occurs as a result of someone putting his money where his mouth is.) If you're just looking to dump money into broad market indicies in a leveraged fashion, you're doing it wrong. There is no free money. (Ed. Which is not to say there's not money. There's lots of money. But if you go looking for the free kind, you won't find it, and may end up with money that you thought was free but was actually quite expensive.) Edit. Okay, so you don't like my answer. I'm not surprised. I'm giving you a real answer instead of a ""make free money"" answer. Okay. Here's your ""how to make free money"" answer. Assume you are using a constant leverage ratio over the length of time you've invested your money, and you don't get to just jump into and out of the market (that's market-timing, not leverage) so you have to stay invested. You're going to have a scenario which falls into one of these categories: The S&P500 historically rises over time. The average rate of return probably exceeds the average interest rate. So the ideal leverage ratio is infinite. Of course, this is a stupid answer in real life because you can't pull that off. Your risk tolerance is too low and you will have trouble finding a lender willing to lend you unsecured money, and you'll probably lose all your money in a crash sooner or later. Ultimately it's a stupid answer because you're asking the wrong question. You should probably ask a better question: ""when I use leverage to gain additional exposure to risk, am I being properly compensated for assuming that risk?"""
I agree with others here that suggest that you should be taking higher risk since it is repaid with higher returns. You have 40 years or so to go before you might switch to safer but lower return funds. I suggest that you look at the Morningstar rating for the funds you are considering: http://www.morningstar.com/ A fund rated five stars means that the fund performs in the top 20% compared to all similar funds. I prefer five star funds. Next, check the management fees. Here is an example from one of the funds you mentioned; https://www.google.com/finance?cid=466533039917726 Next, I suggest you compare how each fund has performed compared to a benchmark. Here are some common indices:  Compare an equity fund to, for example, the S&P 500. Has your fund beat or closely matched the S&P for 1, 5 and 10 years? If not, you may as well buy an index fund, such as SPY. The S&P 500 is a market index.  The P/E data you're finding for the S&P 500 is data based on the constituent list of that market index and isn't necessarily the P/E ratio of a given fund, even one that aims to track the performance of the S&P 500.    I'm sure similar metrics exist for other market indexes, but unless Vanguard is publishing it's specific holdings in it's target date funds there's no market index to look at. For video games the S&amp;P home entertainment software index will probably work. For airlines there's the S&amp;P airlines index but that may not work well for private jets.  You should browse different S&amp;P indicies based on GICS classifications or any other indicies you may find and then download their returns for the past few years and run a regression analysis on excel. Find the correlation between the indicies and the stock you're looking at then select the index with the highest correlation. Fire your fund manager. There are several passive funds that seek to duplicate the S&P 500 Index returns. They have lower management fees, which will make returns lower than S&P, and they have less risk by following a broadly diversified strategy (versus midcap growing stocks). There's also ETFs, but evidence is growing that they're not as safe as hoped. But here's the deal: the S&P has been on a tear lately. It could be overvalued and what looks like a good investment could start falling again. A possible alternative would be one of the Lifetime funds that seek to perform portfolio adjustment with a retirement decade target; they're fairly new which mostly means nobody knows how they screw you over yet. In theory, this decade structure means the brokerage can execute trading cash for stocks, stocks for bonds, and bonds for cash in house. If your gut told you to buy during the depths of '09, your gut might be well-calibrated. The problem is stock market declines during recessions are frequently not that large relative to the average long run return of 9%:  A better strategy might be hold a percentage in equities based upon a probability distribution of historical returns.  This becomes problematic because of changes in the definition of earnings and the recent inflation stability which has encouraged high valuations:  Cash flow has not been as corrupted as earnings now, and might be a better indicator:  This obviously isn't perfect either, but returns can be improved. Since there is no formulaic way yet conventionally available, the optimal primary strategy is still buy & hold which has made the most successful investor frequently one of the richest people on the planet for decades, but this could still be used as an auxiliary for cash management reserves during recessions once retired. I wouldn't call it apples and oranges.  This is literally an opportunity cost calculation.  You can safely assume S&P500 will perform at least 11% over any 10 year period.  Since failing companies are delisted and replaced with new growing companies, the market should continue to grow.  No, it's not guaranteed.  Lets use an aggressive number for inflation, 4%, leaving a 7% ROR estimate for S&P500.  I assume OP has better credit than me, assume a rate around 3.5%.  So it looks like net 3.5% ROR.  The PMI erases that.  You have to continue paying it until you pay off the loan.   Put 20% down, get a 15 year fixed at lowest rate.  Pay it off quicker. Fund performance at NAV (%) for latest quarter, YTD, and average annual total returns for 1, 3, 5, 10 years. P/E ratio (1 yr. forecast), P/B ratio, Beta, Sharpe ratio, Wtd. avg. market cap, fund assets.  I guess I would want to calculate all these things based off of the data that I would be working with. I will assume I am working with daily fund values per share over 10+ years. I have asked myself this exact same question many times. The analysis would be simple if you invested all your money in a single day, but I did not and therefore I would need to convert your cash transactions into Index fund buys/sells. I got tired of trying to do this using Yahoo's data and excel so I built a website in my spare time. I humbly suggest you try my website out in the hopes that it helps you perform this computation: http://www.amibeatingthemarket.com/