Periodicity in stock charts
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.
FreeStockCharts.com keeps some intra-day trading history.  You have to create an account to look up individual stocks.  Once you create a free account you can get intra-day trading history for the last month (Hourly for past month, 15 minutes for past week, 1 minute for past day).  Going back past one month and it only keeps daily close history. Here is Family Dollary's (FDO) hourly intra-day chart for the past month: "You could use any of various financial APIs (e.g., Yahoo finance) to get prices of some reference stock and bond index funds.  That would be a reasonable approximation to market performance over a given time span. As for inflation data, just googling ""monthly inflation data"" gave me two pages with numbers that seem to agree and go back to 1914.  If you want to double-check their numbers you could go to the source at the BLS. As for whether any existing analysis exists, I'm not sure exactly what you mean.  I don't think you need to do much analysis to show that stock returns are different over different time periods." 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... There are Patterns inside of Patterns. You will see short term patterns (flags / pennants) inside of long term patterns (trend lines, channels) and typically you want to trade those short term patterns in line with the direction of the long term pattern.  Take a look at the attached chart of GPN. I would like to recommend two excellent books on Chart Patterns. Richard W. Schabacker book he wrote in the 1930's. It is the basis for modern technical pattern analysis.  Technical Analysis and Stock Market Profits  Peter Brandt Diary of a Professional Commodity Trader. He takes you through analysis and trades. You can likely use bollinger band values to programmatically recognize sideways trending stocks. Bollinger band averages expand during periods of volatility and then converge on the matched prices the longer there is little volatility in the asset prices. Also, look at the bollinger band formula to see if you can glean how that indicator does it, so that you can create something more custom fit to your idea. The last column in the source data is volume (the number of stocks that was exchanged during the day), and it also has a value of zero for that day, meaning that nobody bought or sold the stocks on that day. And since the prices are prices of transactions (the first and the last one on a particular day, and the ones with the highest/lowest price), the prices cannot be established, and are irrelevant as there was not a single transaction on that day. Only the close price is assumed equal to its previous day counterpart because this is the most important value serving as a basis to determine the daily price change (and we assume no change in this case). Continuous-line charts also use this single value. Bar and candle charts usually display a blank space for a day where no trade occurred. id like to start by saying youre still doing this yourself, and i dont actually have all the info required anyway, dont send it but  &gt;[3] Descriptive Statistical Measures: Provide a thorough discussion of the meaning and interpretation of the four descriptive &gt;statistical measures required in your analysis: (1) Arithmetic Mean, (2) Variance, (3) Standard Deviation and (4) Coefficient of &gt;Variation. For example, how are these measures related to each other? In order to develop this discussion, you may want to &gt;consult chapters 2 and 3 of your textbook. This topic is an important part of your report. can be easily interpreted, im guessing the mean is simply just the observed (and then projected stock price for future models) the standard deviation determines the interval in which the stock price fluctuates. so you have like a curve, and then on this curve theirs a bunch of normal distributions modeling the variance of the price plotted against the month  also the coefficient of variation is just r^2 so just read up on that and relate it to the meaning of it to the numbers you have  actually my stats are pretty rusty so make sure you really check into these things  but otherwise the formulas for part 4 is simple too. you can compare means of a certain month using certain equations, but there are different ones for certain situations  you can test for significance by comparing the differences of the means and if its outside of your alpha level then it probably means your company is significantly different from the SP index. (take mu of SP - mu of callaway)  you can also find more info on interpreting the two different coefficients your given if you look up comparing means of linear regression models or something Graphs are nothing but a representation of data. Every time a trade is made, a point is plotted on the graph. After points are plotted, they are joined in order to represent the data in a graphical format.  Think about it this way.  1.) Walmart shuts at 12 AM. 2.)Walmart is selling almonds at $10 a pound.  3.) Walmart says that the price is going to reduce to $9 effective tomorrow. 4.) You are inside the store buying almonds at 11:59 PM.  5.) Till you make your way up to the counter, it is already 12:01 AM, so the store is technically shut. 6.) However, they allow you to purchase the almonds since you were already in there.  7.) You purchase the almonds at $9 since the day has changed. 8.) So you have made a trade and it will reflect as a point on the graph. 9.) When those points are joined, the curves on the graph will be created. 10.) The data source is Walmart's system as it reflects the sale to you. ( In your case the NYSE exchange records this trade made). Buying a stock is just like buying almonds. There has to be a buyer. There has to be a seller. There has to be a price to which both agree. As soon as all these conditions are met, and the trade is made, it is reflected on the graph. The only difference between the graphs from 9 AM-4 PM, and 4 PM-9 AM is the time. The trade has happened regardless and NYSE(Or any other stock exchange) has recorded it! The graph is just made from that data. Cheers. "IMO: If you look long and hard enough at your data you're going to bump into these kinds of ""patterns"". There is no ""curse of 7"".  “Looking at the chart makes you want to hide under your desk when you see it, but remember this is only a sample size of 11, and the average performance is greatly skewed by big drops late in 1907, 1937, 1957, and 1987. Also, consider that 1907, 1937, and 1957 were all recessionary years, and equities had run up 40% for the year in August 1987, so a pullback was not surprising."" [Quote](https://lplresearch.com/2017/08/11/the-curse-of-years-ending-in-7/)" "The charts on nasdaq.com are log based, if you look closely you can see that the spacing between evenly incremented prices is tighter at the top of the chart and wider at the bottom.   It's easiest to see on a stock with a wide price range using candlestick where you can clearly see the grid.  I'm also not seeing the ""absurdism"" you indicate when I look at google finance with the settings ticked to use log on the price axis.  I see what I'd expect which is basically a given vertical differential on the price axis representing the same percentage change in price no matter where it is located. For example if I look at GOOG from the earliest date they have (Aug 20 2004) to a nice high point (dec 7 2007) I see a cart where the gap from the the bottom of the chart (seems to be right around 100) to the 200 point, (a 100% increase) is the same as from 200 to 400 (a 100% increase) is the same as 400 to 800 (a 100# increase)   That's exactly what I expect from a 'log' chart on a financial site, each relative move up or down of the same distance, represents the same relative change in value. So I'm having difficulty understanding what your complaint is. (note: I'm using chrome, which is the browser I'd expect to work best with any google website.  results with other browsers could of course vary)  If you want to do some other wacky math with the axis then I humbly suggest that something like Excel is your friend.   Goto the charts at nasdaq.com  get the chart displaying the period you care about, click the chart to display the unlying data, there will be an option to download the data.  cram it into excel and go wild as you want with charting it out.  e.g. note that step 2 links to client side javascript, so you will need javascript enabled, if you are running something like noscript, disable it for this site.  Also since the data opens in a new window, you may also need to enabled 'popups' for the site. (and yes, I sometimes get an annoying news alert advert popup  and have to close it when the chart first appears.. oh well it pays the rent and nasdaq is not charging you so for access so such is the price for a free site. )" "This is called ""change"" or ""movement"" - the change (in points or percentage) from the last closing value. You can read more about the ticker tape on Investopedia, the format you're referring to comes from there." 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. A simple strategy for this is shown in the chart below:  I would be buying this stock when the price hits or gets very close to the trendline and then it bounces back above it. I would then have sold this stock once it has broken through below the trendline. This may also be an appropriate time if you were looking to short this stock. Other indicators could also be used in combination for additional confirmation of what is happening to the price. Another type of trader is called a bottom fisher. A bottom fisher would wait until a break above the downtrend line (second chart) and buy after confirmation of a higher high and possibly a higher low (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, whether you prefer short term trading or longer term investing, and your appetite for risk. You can develop strategies using various indicators and then paper trade or backtest these strategies. You can also manually backtest a strategy in most charting packages. You can go back in time on the chart so that the right side of the chart shows a date in the past (say one year ago or 10 years ago), then you can click forward one day at a time (or one week at a time if using weekly charts). With your indicators on the chart you can do virtual trades to buy or sell whenever a signal is given as you move forward in time. This way you may be able to check years of data in a day to see if your strategy works. Whatever you do, you need to document your strategies in writing in a written trading or investment plan together with a risk management strategy. You should always follow the rules in your written plan to avoid you making decisions based on emotions. By backtesting or paper trading your strategies it will give you confidence that they will work over the long term.  There is a lot of work involved at the start, but once you have developed a documented strategy that has been thoroughly backtested, it will take you minimal time to successfully manage your investments. In my shorter term trading (positions held from a couple of days to a few weeks) I spend about half an hour per night to manage my trades and am up about 50% over the last 7 months. For my longer term investing (positions held from months to years) I spend about an hour per week and have been averaging over 25% over the last 4 years. Technical Analysis does work for those who have a documented plan, have approached it in a systematic way and use risk management to protect their existing and future capital. Most people who say that is doesn't work either have not used it themselves or have used it ad-hock without putting in the initial time and work to develop a documented and systematic approach to their trading or investing. James Roth provides a partial solution good for stock picking but let's speed up process a bit, already calculated historical standard deviations: Ibbotson, very good collection of research papers here, examples below Books "By definition, there are no guaranteed profits. There are sometimes arbitrage opportunities, which are more accessible to some investors than others. In this case, I'm not referring to HFT as that is covered elsewhere on this site already.  At certain times, in certain equity markets, candlestick charts were used for profitable trading, though more for trades set up for weeks or months, not day trading. I am referring specifically to Nikkei 225 equities, in the 1980's and 1990's. I don't know why it was effective, and it hasn't worked for me since then. I recommend reading and heeding this answer. Some people DO use technical analysis (see ""TA is not..."" section) as a primary trading strategy, but they are not going to divulge their methods, not here nor anywhere else." 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.