Evidence for/against negative correlation between commodity futures, stocks
"The correlation I heard most about in economics/finance was that stock prices and bond yields were negatively correlated; as the stock market does better, bond yields fall (company's doing well as evidenced by stocks, so it's a good credit risk, so YTM of its bonds on the market goes down). The correlation, if any, between the stock and futures market should be visible in the actual price histories. Index prices may be useful, but what's more likely is that various future prices have correlation with various companies' stocks. Where the future reflects the price of a raw material that is a significant cost of goods sold for a company, you'll see these two move inversely to each other in the short term. I think that if there is a causative relationship here, its that futures prices influence stock prices, not the other way around. The futures market generally represents the cost side of a consumer goods producer's bottom line. The stock market represents its profits. As futures go up, profit expectations go down, putting pressure on stock prices. Industries that deal in services, or in other types of goods, can still be affected because a rise in the cost of something consumers need will cause them to spend less on other things which affects margins in those other areas. So, in the short and medium term, when the futures market goes up the stock market sees a dip, and vice versa.  However, companies adapt; they can put upward pressure on prices for their goods to restore their desired margins, usually by slowly increasing them to prevent sticker shock (though elasticity of demand plays a part; the more we need something no matter what it costs, the faster prices can increase). To maintain costs, they can make things cheaper using less expensive materials (more plastic, less steel). They can restructure production processes (translated: move factories offshore, or at least to ""right-to-work"" states with less union strength) to save costs elsewhere. All of these reduce costs and thus increase profits, but take time to implement. Many of these things reduce direct costs, reducing demand for the commodity and causing the futures prices to go back down. So, over the long term, these differences even out, and it's down to the things that affect the entire market (inflation, consumer/investor confidence, monetary policy)."
"I agree completely.  ""I don't always agree with John Cochrane, but when I do, I agree completely.""  I think heavy reliance on either approach to pricing is generally a bad idea.  Equilibrium models always include something that you're supposed to inherently know, but never do.  No-arbitrage models don't necessarily *say* anything that you don't (in some mathematical sense) already know.  So you're either stuck with unknown parameters, or you can't explain why you're something is worth what you say it is beyond, ""Herp derp, other people are doing it.""  So I think if buy-side people made some use of no-arbitrage models, they'd have a better understanding of the parameters they're making up, and if sell-side people sometimes used equilibrium models, they'd have a better grasp of what's going on economically.  Also, it would have the beneficial effect of reminding people that their models are always wrong, even if they're frequently useful." It is called the Monday Effect or the Weekend Effect. There are a number of similar theories including the October Effect and January Effect. It's all pretty much bunk. If there were any truth to traders would be all over it and the resulting market forces would wipe it out. Personally, I think all technical analysis has very little value other than to fuel conversations at dinner parties about investments. You might also consider reading about Market efficiency to see further discussion about why technical approaches like this might, but probably don't work. Context is key here. Futures don't really have to do with a time in the future in this context.  Futures are a capital market (futures market), just like Stocks are a market (stock market). Both capital markets have the ability to affect each other. Up until 30 years ago there was a separate use for the futures market, but in the days since they are MOSTLY used for stock derivatives (financial futures are the most widely traded contracts since 1980, hugely eclipsing the commodity futures that the market was designed for.)  So there is overlap and one affect the other, I'm not going to go into too much detail here but basically the futures market trades 24 hours a day, 6.5 days of the week and the  stock market trades 8-12 hours a day, 5 days a week.  So when the stock market closes, the futures market is still running will react and effect the broad stock market.  Hope that gets you started in your research "Maria, there are a few questions I think you must consider when considering this problem. Do fundamental or technical strategies provide meaningful information? Are the signals they produce actionable? In my experience, and many quantitative traders will probably say similar things, technical analysis is unlikely to provide anything meaningful. Of course you may find phenomena when looking back on data and a particular indicator, but this is often after the fact. One cannot action-ably trade these observations. On the other hand, it does seem that fundamentals can play a crucial role in the overall (typically long run) dynamics of stock movement. Here are two examples, Technical: suppose we follow stock X and buy every time the price crosses above the 30 day moving average. There is one obvious issue with this strategy - why does this signal have significance? If the method is designed arbitrarily then the answer is that it does not have significance. Moreover, much of the research supports that stocks move close to a geometric brownian motion with jumps. This supports the implication that the system is meaningless - if the probability of up or down is always close to 50/50 then why would an average based on the price be predictive? Fundamental: Suppose we buy stocks with the best P/E ratios (defined by some cutoff). This makes sense from a logical perspective and may have some long run merit. However, there is always a chance that an internal blowup or some macro event creates a large loss.  A blended approach: for sake of balance perhaps we consider fundamentals as a good long-term indication of growth (what quants might call drift). We then restrict ourselves to equities in a particular index - say the S&P500. We compare the growth of these stocks vs. their P/E ratios and possibly do some regression. A natural strategy would be to sell those which have exceeded the expected return given the P/E ratio and buy those which have underperformed. Since all equities we are considering are in the same index, they are most likely somewhat correlated (especially when traded in baskets). If we sell 10 equities that are deemed ""too high"" and buy 10 which are ""too low"" we will be taking a neutral position and betting on convergence of the spread to the market average growth. We have this constructed a hedged position using a fundamental metric (and some helpful statistics). This method can be categorized as a type of index arbitrage and is done (roughly) in a similar fashion. If you dig through some data (yahoo finance is great) over the past 5 years on just the S&P500 I'm sure you'll find plenty of signals (and perhaps profitable if you calibrate with specific numbers). Sorry for the long and rambling style but I wanted to hit a few key points and show a clever methods of using fundamentals." Is it just -34*4.58= -$155.72 for CCC and -11*0.41= -$4.51 for DDD? Yes it needs to be recorded as negative because at some point in time, the investor will have to spend money to buy these shares [cover the short sell and return the borrowed shares]. Whether the investor made profit or loss will not be reflected as you are only reflecting the current share inventory. Its the relative leverage available to retail traders between the two.  In the US one can trade equities with 2:1 leverage while with commodities the leverage can go much higher.  Combine this with the highly volatile nature of commodities, and it makes losing BIG too easy for the average trader. I understand now. Thank you. How important is the existence of effective price discovery tools in a market?   And the example that you gave of a farmer is good, but when I as the owner of a company, get futures regarding, say, the stocks that I own of my company, won't that be insider trading if I do that after knowing that the value of my stocks will fall? If people assume price discovery in this case, won't they also have to assume that I am doing insider trading? 1. It doesn't have an almost perfect negative correlation - its value decays very fast because of time.  In fact, something like 80% of options expire worthless.  They typically have a lifespan of 30-90 days and unless you're using them as a way to earn excess return, you'll likely just throw away your premium.  2. You're also making some assumptions about correlation and risk/reward.  You won't become wealthy by distributing risk, all you can hope for is less volatility - maybe that's what you're looking for - but you can also expect your return to be less than the market over almost any period of time.  3. Options aren't really for diversifying.  Furthermore, why diversify?  It's a myth that it adds any value.  There's around a 90% correlation for all asset classes since around 2000, so you're being sold some blue sky if someone tells you otherwise.  4. Look up prices of put options.  1-2% of your portfolio might buy you a handful of options, but again, there's a high probability you'll lose that 1-2% entirely every 30-90 days. Your question is a moving target. And my answer will be subject to revision. I disagree with the votes to close, as you are asking (imho) what role commodities and specifically oil, play in one's asset allocation. Right? How much may be opinion, but there's a place to ask if.  I'm looking at this chart, and thinking, long term, the real return is zero. The discussion regarding gold has been pretty exhausted. For oil, it's not tough to make the case that it will fluctuate, but long term, there's no compelling reason to believe its price will rise any faster than inflation over the really long term. "Strategy would be my top factor.  While this may be implied, I do think it helps to have an idea of what is causing the buy and sell signals in speculating as I'd rather follow a strategy than try to figure things out completely from scratch that doesn't quite make sense to me. There are generally a couple of different schools of analysis that may be worth passing along: Fundamental Analysis:Fundamental analysis of a business involves analyzing its financial statements and health, its management and competitive advantages, and its competitors and markets. When applied to futures and forex, it focuses on the overall state of the economy, interest rates, production, earnings, and management. When analyzing a stock, futures contract, or currency using fundamental analysis there are two basic approaches one can use; bottom up analysis and top down analysis. The term is used to distinguish such analysis from other types of investment analysis, such as quantitative analysis and technical analysis. Technical Analysis:In finance, technical analysis is a security analysis methodology for forecasting the direction of prices through the study of past market data, primarily price and volume. Behavioral economics and quantitative analysis use many of the same tools of technical analysis, which, being an aspect of active management, stands in contradiction to much of modern portfolio theory. The efficacy of both technical and fundamental analysis is disputed by the efficient-market hypothesis which states that stock market prices are essentially unpredictable. There are tools like ""Stock Screeners"" that will let you filter based on various criteria to use each analysis in a mix.  There are various strategies one could use.  Wikipedia under Stock Speculator lists: ""Several different types of stock trading strategies or approaches exist including day trading, trend following, market making, scalping (trading), momentum trading, trading the news, and arbitrage.""  Thus, I'd advise research what approach are you wanting to use as the ""Make it up as we go along losing real money all the way"" wouldn't be my suggested approach. There is something to be said for there being numerous columnists and newsletter peddlers if you want other ideas but I would suggest having a strategy before putting one's toe in the water." "No. Some grocery stores may discount specific products based on inventory to drive sales using ""loss leaders"" where the product is intentionally priced as a loss for the business. While commodity futures may impact some prices, I'm not sure one can easily extract the changes solely due to futures shifts." The main advantage of commodities to a largely stock and bond portfolio is diversification and the main disadvantages are investment complexity and low long-term returns. Let's start with the advantage.  Major commodities indices and the single commodities tend to be uncorrelated to stocks and bonds and will in general be diversifying especially over short periods.  This relationship can be complex though as Supply can be even more complicated (think weather) so diversification may or may not work in your favor over long periods. However, trading in commodities can be very complex and expensive.  Futures need to be rolled forward to keep an investment going.  You really, really don't want to accidentally take delivery of 40000 pounds of cattle.  Also, you need to properly take into account roll premiums (carry) when choosing the closing date for a future.  This can be made easier by using commodities index ETFs but they can also have issues with rolling and generally have higher fees than stock index ETFs. Most importantly, it is worth understanding that the long-term return from commodities should be by definition (roughly) the inflation rate.  With stocks and bonds you expect to make more than inflation over the long term.  This is why many large institutions talk about commodities in their portfolio they often actually mean either short term tactical/algorithmic trading or long term investments in stocks closely tied to commodities production or processing. The two disadvantages above are why commodities are not recommended for most individual investors. "In theory, the idea is that diversified assets will perform differently in different circumstances, spreading your risk around. Whether that still functions in practice is a decent question, as the ""truth"" of most probability based arguments for diversification rely on the different assets being at least somewhat uncorrelated. This article suggests that might not be true. Specifically: The correlations we note among industry sectors are profoundly and dysfunctionally high. and  Gold and silver traders have gotten too used to the negative correlation trade with stocks. This is, in fact, an unusual relationship for precious metals tostocks. The correlation should actually be zero." Auto-correlation is a statistical concept for measuring repeating patterns in series.  In stocks it is of particular interest as if future prices can be reliably guessed from past prices a lot of money could be made.   Note, even in cases where auto-correlations are high and persistent (near 1) there is still some possibility that the next time period would be down even if the previous period was up.  Now the important part here is that high and persistent auto-correlation also means once the price falls the next period the price is also more likely to fall! Once one period was down the next period is more likely to be down so the price does not need to go to infinity.  Instead, it generally would display up and down trends. Now, the key word above for investing is persistence. For stocks, auto-correlations are, at best, weakly persistent at reasonable time scales.  So, even if a stock was highly auto-correlated during a previous period it is tough to make consistent money off of trading on these past trending patterns.  This does not mean some people don't try... Yes, it makes sense. Like Lagerbaer says, the usefulness of technical indicators can not be answered with a simple yes or no. Some people gain something from it, others do not. Aside from this, applying technical indicators (or any other form of technical analysis - like order flow) to instruments which are composed of other instruments, such as indexes (more accurately, a derivative of it), does make sense. There are many theories why this is the case, but personally i believe it is a mixture of self fulfilling prophecy, that the instruments the index is composed of (like the stocks in the S&P500) are traded in similar ways as the index (or rather a trade-able derivative of it like ETFs and futures), and the idea that TA just represents human emotion and interaction in trading. This is a very subjective topic, so take this with a grain of salt, but in contrast to JoeTaxpayer i believe that yields are not necessary in order to use TA successfully. As long as the given instrument is liquid enough, TA can be applied and used to gain an edge. On the other hand, to answer your second question, not all stocks in an index correlate all the time, and not all of them will move in sync with the index.