Project future trend of a stock with high positive autocorrelation
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...
I have read in many personal finance books that stocks are a great investment for the long term, because on average they go up 5-7% every year. This has been true for the last 100 years for the S&P500 index, but is there reason to believe this trend will continue indefinitely into the future? It has also been wrong for 20+ year time periods during those last 100 years. It's an average, and you can live your whole career at a loss. There are many things to support the retention of the average, over the next 100 years. I think the quip is out of scope of your actual investment philosophy. But basically there are many ways to lower your cost basis, by reinvesting dividends, selling options, or contributing to your position at any price from a portion of your income, and by inflation, and by the growth of the world economy. With a low enough cost basis then a smaller percentage gain in the index gives you a magnified profit. "Let me start with a somewhat sarcastic statement: There are probably as many things done to analyze a stock as there are people doing the analysis! That said, at a general level an analyst researches the historical performance of the company at a fairly detailed level (operations within divisions of the company, product development cycles within divisions, expenses vs income trends for each division and product, marketing costs, customer acquisition costs, etc); gathers information about what the company is doing now AND planning to do in the future -- often by a discussion with principles at the company; establishes a view on related macro-economic trends, sector and industry trends, demographic trends, etc.; and combines it all to forecast a change in revenues, margins, free cash flow, dividends, etc. over a period of time.   They then apply statistics that relate those numbers to stock price in order to imply stock prices and price ranges over those same periods.  Finally, depending on how those stock prices compare to the current stock price, they'll classify the stock as Buy, Sell, Hold, etc. This sounds like alot of work.   And it generally is if you get detailed about it, which is what professionals or significant money managers are doing.   However, there are also lots of arm-chair analysts posting their output on any number of financial sites (Seeking Alpha, Motley Fool, etc.) if you'd like to really explore the range of detail some people consider as a ""stock analysis"".  That sounds more negative than I intended it to be, so let me clarify that I think some of these write-ups are really quite good IMO." The study of technical analysis is generally used (sometimes successfully) to time the markets. There are many aspects to technical analysis, but the simplest form is to look for uptrends and downtrends in the charts. Generally higher highs and higher lows is considered an uptrend.  And lower lows and lower highs is considered a downtrend.  A trend follower would go with the trend, for example see a dip to the trend-line and buy on the rebound. Whilst a bottom fisher would wait until a break in the downtrend line and buy after confirmation of a higher high (as this could be the start of a new uptrend). There are many more strategies dealing with the study of technical analysis, and if you are interested you would need to find and learn about ones that suit your investment styles and your appetite for risk. The most significant capability that an investor must have is the knowledge on the way to look for the high dividend stocks. Through accumulating good information relating to towards the stocks that you are finding is the better way of getting the perfect and profitable investments. It is really important to learn what makes a particular stock better and superior compared to other.   Traders are essential to start a complete analysis and investigation before getting their money on any business projects. Obviously, investors certainly want to have an investment that could guarantee an effective expense for a very reasonable cost the moment of getting it. The chances of crucial to invest in a market that you might be aware and qualified about. So, creating a comparison and compare in one business to a different is totally essential so as to find the high dividend stock. Keep in mind there are a couple of points to ponder here: Rates are really low. With rates being so low, unless there is deflation, it is pretty easy to see even moderate inflation of 1-2% being enough to eat the yield completely which would be why the returns are negative. Inflation is still relatively contained. With inflation low, there is no reason for the central banks to raise rates which would give new bonds a better rate. Thus, this changes in CPI are still in the range where central banks want to be stimulative with their policy which means rates are low which if lower than inflation rates would give a negative real return which would be seen as a way to trigger more spending since putting the money into treasury debt will lose money to inflation in terms of purchasing power. A good question to ponder is has this happened before in the history of the world and what could we learn from that point in time. The idea for investors would be to find alternative holdings for their cash and bonds if they want to beat inflation though there are some inflation-indexed bonds that aren't likely appearing in the chart that could also be something to add to the picture here. Daily &gt; Weekly &gt; Monthly. This statement says that if you use daily returns you will get more noise than if you used weekly or monthly returns. Much of the research performed uses monthly returns, although weekly returns have been used as well. For HFT you would need to detrend the data in order to spot true turning points. The problem is that short-term trends are really unpredictable.  There is nobody who can accurately predict where a fund (or even moreso, a single stock or bond) is going to move in a few hours, or days or even months. The long-term trends of the entire market, however, are (more or less) predictable.  There is a definite upward bias when you look at time-scales of 5, 10, 20 years and more.  Individual stocks and bonds may crash, and different sectors perform differently from year to year, but the market as a whole has historically always risen over long time scales. Of course, past performance never guarantees future performance.  It is possible that everything could crash and never come back, but history shows that this would be incredibly unlikely.  Which is the entire basis for strategies based on buying and holding (and periodically rebalancing) a portfolio containing funds that cover all market sectors. Now, regarding your 401(k), you know your time horizon.  The laws won't let you withdraw money without penalty until you reach retirement age - this might be 40 years, depending on your current age.  So we're definitely talking long term.  You shouldn't care about where the market goes over a few months if you won't be using the money until 20 years from now. The most important thing for a 401(k) is to choose funds from those available to you that will be as diverse as possible.  The actual allocation strategy is something you will need to work out with a financial advisor, since it will be different for every person.  Once you come up with an appropriate allocation strategy, you will want to buy according to those ratios with every paycheck and rebalance your funds to those ratios whenever they start to drift away.  And review the ratios with your advisor every few years, to keep them aligned with large-scale trends and changes in your life. If it's anything IG that's likely an annualized figure. I previously sold CP over short term windows at 1% annualized. Else, it would generate a high long term gain, but you need to weigh a variety of factors versus gains, particularly if you're investing any meaningful sum of money. I'm not a bond trader.   Unless it's some kind of payday loan...