Market Hours and Valuations
"Company values (and thus stock prices) rely on a much larger time frame than ""a weekend"".  First, markets are not efficient enough to know what a companies sales were over the past 2-3 days (many companies do not even know that for several weeks).  They look at performance over quarters and years to determine the ""value"" of a company.  They also look forward, not backwards to determine value.  Prior performance only gives a hint of what future performance may be.  If a company shut its doors over a weekend and did no sales, it still would have value based on its future ability to earn profits." Stock values are generally reflective of a company's overall potential; and to some extent investor confidence in the prospect of a continued growth of that potential. Sales over such a short period of time such as a single weekend do not noticeably impact a stock's valuation.  A stock's value has more to do with whether or not they meet market expectations for sales over a certain period of time (generally 1 quarter of a year) than it does that they actually had sales (or profits) on any given day. Of course, catastrophic events, major announcements, or new product releases do sometimes cause significant changes in a stock's value.  For this reason you will often see stocks have significant volatility in periods around earnings announcements, merger rumors, or when anything unexpected happens in the world that might benefit or hurt their potential sales and growth. But overall a normal, average weekend of sales is already built into the price of a stock during normal trading.
"This is a good question and my answer below, being the first rationale that crossed my mind, is far from fleshed-out. It's just a reply based on many books on the historical cycles of markets and it's something I've discussed at work (I work in finance).   Historically we can observe that periods of financial ""booms"" entailing high valuations of public equities tend to lead to lower returns. It's a fairly simplistic notion, but if you're paying more now for something - when it's potentially close to a high water mark - then you're returns in the short term are likely to be somewhat stunted. Returns from the underlying companies have a hard time keeping up with high valuations such that investors aren't likely to see a bountiful return in the short run." No, SPDR ETFs are not a good fit for a novice investor with a low level of financial literacy.  In fact, there is no investment that is safe for an absolute beginner, not even a savings account.  (An absolute beginner could easily overdraw his savings account, leading to fees and collections.) I would say that an investment becomes a good fit for an investor as soon as said investor understands how the investment works.  A savings account at a bank or credit union is fairly easy to understand and is therefore a suitable place to hold money after a few hours to a day of research.  (Even after 0 hours of research, however, a savings account is still better than a sock drawer.) Money market accounts (through a bank), certificates of deposit (through a bank), and money market mutual funds (through a mutual fund provider) are probably the next easiest thing to understand.  This could take a few hours to a few weeks of research depending on the learner. Equities, corporate bonds, and government bonds are another step up in complexity, and could take weeks or months of schooling to understand well enough to try.  Equity or bond mutual funds -- or the ETF versions of those, which is what you asked about -- are another level after that. Also important to understand along the way are the financial institutions and market infrastructure that exist to provide these products:  banks, credit unions, public corporations, brokerages, stock exchanges, bond exchanges, mutual fund providers, ETF providers, etc. As other answers have pointed out, professional real estate investors do own residential investment properties. However, small residential units typically are not owned by professional real estate investors as your experience confirms. This has a fairly natural cause. The size of the investment opportunity is insufficient to warrant the proper research/due diligence to which a large investment firm would have to commit if it wanted to properly assess the potential of a property. For a small real estate fund managing, say, $50 MM, it would take 100 properties at a $500K valuation in order to fully invest the funds. This number grows quickly as we decrease the average valuation to reflect even smaller individual units. Analogously, it is unlikely that you will find large institutional investors buying stocks with market caps of $20 MM. They simply cannot invest a large enough portion of total AUM to make the diligence make economic sense.  As such, institutional real estate money tends to find its way into large multi-family units that provide a more convenient purchase size for a fund. "I would differentiate between pricing and valuation a bit more:  Valuation is the result of investment analysis and the result of coming up with a fair value for a company and its shares; this is done usually by equity analysts. I have never heard about pricing a security in this context. Pricing would indicate that the price of a product or security is ""set"" by someone (i.e. a car manufacturer sets the prices of its new cars). The price of a security however is not set by an analyst or an institution, it is solely set by the stock market (perhaps based on the valuations of different analysts).  There is only one exception to this: pricing an IPO before its shares are actually traded on an exchange. In this case the underwriting banks set the price (based on the valuation) at which the shares are distributed." They could have different quotes as there are more than a few pieces here.  Are you talking a Real Time Level II quote or just a delayed quote?  Delayed quotes could vary as different companies would be using different time points in their data.  You aren't specifying exactly what kind of quote from which system are you using here. The key to this question is how much of a pinpoint answer do you want and how prepared are you to pay for that kind of access to the automated trades happening?  Remember that there could well be more than a few trades happening each millisecond and thus latency is something to be very careful here, regardless of the exchange as long as we are talking about first-world stock exchanges where there are various automated systems being used for trading. Different market makers is just a possible piece of the equation here.  One could have the same market maker but if the timings are different,e.g. if one quote is at 2:30:30 and the other is at 2:30:29 there could be a difference given all the trades processed within that second, thus the question is how well can you get that split second total view of bids and asks for a stock.  You want to get all the outstanding orders which could be a non-trivial task. The two answers so far are right, but there's a third factor - for many stocks, there's after hours trading. So the official 4PM close is not what the stock's last trade was when they open again. Regardless, even that after hour price is not the starting point as Muro points out. "First, I would like to use a better chart.  In my opinion, a close of day line chart obscures a lot of important information.  Here is a daily OHLC log chart:  The initial drop from the 1099.23 close on Oct 3 was to 839.8 intraday, to close at 899.22 on Oct 10.  After this the market was still very volatile and reached a low of 747.78 on Nov 20, closing only slightly higher than this.  It traded as high as 934.70 on Jan 6, 2009, but the whole period of Nov 24 - Feb 13 was somewhat of a trading range of roughly 800-900.  Despite this, the news reports of the time were frequently saying things like ""this isn't going to be a V shaped recovery, it is going to be U shaped.""  The roughly one week dip you see Feb 27 - Mar 9 taking it to an intraday low of 666.79 (only about 11% below the previous low) on first glance appears to be just a continuation of the previous trend.   However... The Mar 10 uptrend started with various news articles (such as this one) which I recall at the time suggested things like reinstating the parts of the Glass–Steagall Act of 1933 which had been repealed by the Gramm–Leach–Bliley Act.  Although these attempts appear to have been unsuccessful, the widespread telegraphing of such attempts in the media seemed to have reversed a common notion which I saw widespread on forums and other places that, ""we are going to be in this mess forever, the market has nowhere to go but down, and therefore shorting the market is a good idea now.""  I don't find the article itself, but one prominent theme was the ""up-tick"" rule on short selling: source From this viewpoint, then, that the last dip was driven not so much by a recognition that the economy was really in the toilet (as this really was discounted in the first drop and at least by late November had already been figured into the price).  Instead, it was sort of the opposite of a market top, where now you started seeing individual investors jump on the band-wagon and decide that now was the time for a foray into selling (short).  The fact that the up-tick rule was likely to be re-instated had a noticeable effect on halting the final slide." Not really. You can have two bonds that have identical duration but vastly different convexity.   Pensions and insurance portfolio managers are most common buyers as they're trying to deal with liability matching and high convexity allows them to create a barbell around their projected liabilities.