How do markets “factor in” a future event?
"At the most fundamental level, every market is comprised of buyers and selling trading securities. These buyers and sellers decide what and how to trade based on the probability of future events, as they see it. That's a simple statement, but an example demonstrates how complicated it can be. Picture a company that's about to announce earnings. Some investors/traders (from here on, ""agents"") will have purchased the company's stock a while ago, with the expectation that the company will have strong earnings and grow going forward. Other agents will have sold the stock short, bought put options, etc. with the expectation that the company won't do as well in the future. Still others may be unsure about the future of the company, but still expecting a lot of volatility around the earnings announcement, so they'll have bought/sold the stock, options, futures, etc. to take advantage of that volatility.  All of these various predictions, expectations, etc. factor into what agents are bidding and asking for the stock, its associated derivatives, and other securities, which in turn determines its price (along with overall economic factors, like the sector's performance, interest rates, etc.) It can be very difficult to determine exactly how markets are factoring in information about an event, though. Take the example in your question. The article states that if market expectations of higher interest rates tightened credit conditions... In this case, lenders could expect higher interest rates in the future, so they may be less willing to lend money now because they expect to earn a higher interest rate in the future. You could also see this reflected in bond prices, because since interest rates are inversely related to bond prices, higher interest rates could decrease the value of bond portfolios. This could lead agents to sell bonds now in order to lock in their profits, while other agents could wait to buy bonds because they expect to be able to purchase bonds with a higher rate in the future.  Furthermore, higher interest rates make taking out loans more expensive for individuals and businesses. This potential decline in investment could lead to decreased revenue/profits for businesses, which could in turn cause declines in the stock market. Agents expecting these declines could sell now in order to lock in their profits, buy derivatives to hedge against or ride out possible declines, etc. However, the current low interest rate environment makes it cheaper for businesses to obtain loans, which can in turn drive investment and lead to increases in the stock market. This is one criticism of the easy money/quantitative easing policies of the US Federal Reserve, i.e. the low interest rates are driving a bubble in the stock market. One quick example of how tricky this can be. The usual assumption is that positive economic news, e.g. low unemployment numbers, strong business/residential investment, etc. will lead to price increases in the stock market as more agents see growth in the future and buy accordingly. However, in the US, positive economic news has recently led to declines in the market because agents are worried that positive news will lead the Federal Reserve to taper/stop quantitative easing sooner rather than later, thus ending the low interest rate environment and possibly tampering growth.  Summary: In short, markets incorporate information about an event because the buyers and sellers trade securities based on the likelihood of that event, its possible effects, and the behavior of other buyers and sellers as they react to the same information. Information may lead agents to buy and sell in multiple markets, e.g. equity and fixed-income, different types of derivatives, etc. which can in turn affect prices and yields throughout numerous markets."
"replace ""new member acquisition"" with ""new loans"" and see how true your statement isn't.  ...but more fundamentally, there are two factors that exclude banks from ponzi scheme membership:  1 - the thing they create is not in finite supply (they create money at a 10 to 1 rate by encumbering future labor proceeds).  Technically, one could argue that future labor proceeds *are* the thing that does have a finite supply.  I've never seen **anyone** post an estimate of the maximum supply of future labor proceeds (which is totally adjustable via inflation).  2 - they lend at a higher interest rate than they pay.  Technically, all they have to do is keep the time value of money under control with respect of inflation over the duration of loans and they're good." I would not argue if its more difficult, its different, and it much depends what kind of stocks you refer to, i take large caps as example. The players are different. Companies and even govts may hedge in the commodities (futures) market while in big caps this and other entities mainly invest. (Of course there’s HFT in large caps too). Futures often come with way higher leverage, lower spread and less commissions than stocks attracting retail and institutional speculators/HFT. Another big difference is that commodity prices react to all kind of news events (Stocks do too, but not that much and frequent), this kind of reactions big caps only do on earnings or on news directly affecting the company. Commodities are much more volatile on geo economic / political news events. This combined with higher leverage & HFT produces astounding moves.  To sum it up, the players are different and act different than in large stocks, liquidity may be another thing. "Pay cash.  You have the cash to pay for it now, but God forbid something happen to you or your wife that requires you to dip into that cash in the future. In such an event, you could end up paying a lot more for your home theater than you planned. The best way to keep your consumer credit card debt at zero (and protect your already-excellent credit) is to not add to the number of credit cards you already have.   At least in the U.S., interest rates on saving accounts of any sort are so low, I don't think it's worthwhile to include as a deciding factor in whether not you ""borrow"" at 0% instead of buying in cash." "I thought the other answers had some good aspect but also some things that might not be completely correct, so I'll take a shot. As noted by others, there are three different types of entities in your question:  The ETF SPY, the index SPX, and options contracts. First, let's deal with the options contracts.  You can buy options on the ETF SPY or marked to the index SPX.  Either way, options are about the price of the ETF / index at some future date, so the local min and max of the ""underlying"" symbol generally will not coincide with the min and max of the options.  Of course, the closer the expiration date on the option, the more closely the option price tracks its underlying directly.  Beyond the difference in how they are priced, the options market has different liquidity, and so it may not be able to track quick moves in the underlying. (Although there's a reasonably robust market for option on SPY and SPX specifically.) Second, let's ask what forces really make SPY and SPX move together as much as they do.  It's one thing to say ""SPY is tied to SPX,"" but how?  There are several answers to this, but I'll argue that the most important factor is that there's a notion of ""authorized participants"" who are players in the market who can ""create"" shares of SPY at will.  They do this by accumulating stock in the constituent companies and turning them into the market maker.  There's also the corresponding notion of ""redemption"" by which an authorized participant will turn in a share of SPY to get stock in the constituent companies. (See http://www.spdrsmobile.com/content/how-etfs-are-created-and-redeemed and http://www.etf.com/etf-education-center/7540-what-is-the-etf-creationredemption-mechanism.html) Meanwhile, SPX is just computed from the prices of the constituent companies, so it's got no market forces directly on it.  It just reflects what the prices of the companies in the index are doing. (Of course those companies are subject to market forces.) Key point: Creation / redemption is the real driver for keeping the price aligned.  If it gets too far out of line, then it creates an arbitrage opportunity for an authorized participant.  If the price of SPY gets ""too high"" compared to SPX (and therefore the constituent stocks), an authorized participant can simultaneously sell short SPY shares and buy the constituent companies' stocks.  They can then use the redemption process to close their position at no risk.  And vice versa if SPY gets ""too low."" Now that we understand why they move together, why don't they move together perfectly.  To some extent information about fees, slight differences in composition between SPY and SPX over time, etc. do play.  The bigger reasons are probably that (a) there are not a lot of authorized participants, (b) there are a relatively large number of companies represented in SPY, so there's some actual cost and risk involved in trying to quickly buy/sell the full set to capture the theoretical arbitrage that I described, and (c) redemption / creation units only come in pretty big blocks, which complicates the issues under point b. You asked about dividends, so let me comment briefly on that too.  The dividend on SPY is (more or less) passing on the dividends from the constituent companies. (I think - not completely sure - that the market maker deducts its fees from this cash, so it's not a direct pass through.)  But each company pays on its own schedule and SPY does not make a payment every time, so it's holding a corresponding amount of cash between its dividend payments.  This is factored into the price through the creation / redemption process.  I don't know how big of a factor it is though." Timing the market and by extension the efficient market hypothesis is one of the most hotly debated subjects in finance academia. If you are to believe the majority of finance professors and PHD's out there chances of timing a market like the NYSE, NASDAQ or LSE is not possible. If you are to take into account the huge amount of hedge funds and money managers who make it their job to prove the efficient market hypothesis wrong then you may have a chance. My opinion is that the EMH is true and that timing a highly efficient market like the NYSE is very difficult or impossible even for those who spend their whole lives trying to beat it. For someone whose primary job isn’t in investments I would put the idea of timing the markets out of your head. "Futures are an agreement to buy or sell something in the future.  The futures ""price"" is the price at which you agree to make the trade.  This price does not indicate what will happen in the future so much as it indicates the cost of buying the item today and holding it until the future date.  Hence, for very liquid products such as stock index futures, the futures price is a very simple function of today's stock index value and current short-term interest rates.  If the stock exchange is closed but the futures exchange is open, then using the futures price and interest rates one can back out an implied ""fair value"" for the index, which is in essence the market's estimate of what the stock index value would be right now if the stock market were open.  Of course, as soon as the stock exchange opens, the futures price trades to within a narrow band of the actual index value, where the size of the band depends on transaction costs (bid-ask spread, commissions, etc.)." "I always liked the answer that in the short term, the market is a voting machine and in the long term the market is a weighing machine. People can ""vote"" a stock up or down in the short term.   In the long term, typically, the intrinsic value of a company will be reflected in the price. It's a rule of thumb, not perfect, but it is generally true. I think it's from an old investing book that talks about ""Mr. Market"".   Maybe it's from one of Warren Buffet's annual letters.    Anyone know? :)" If the period is consistent for company X, but occurs in a different month as Company Y, it might be linked to the release of their annual report, or the payment of their annual dividend. Companies don't have to end their fiscal year near the end of the Calendar year, therefore these end of year events could occur in any month. The annual report could cause investors to react to the hard numbers of the report compared to what wall street experts have been predicting. The payment of an annual dividend will also cause a direct drop in the price of the stock when the payment is made. There will also be some movement in prices as the payment date approaches.