How useful is the PEG Ratio for large cap stocks?
It is not so useful because you are applying it to large capital. Think about Theory of Investment Value. It says that you must find undervalued stocks with whatever ratios and metrics. Now think about the reality of a company. For example, if you are waiting KO (The Coca-Cola Company) to be undervalued for buying it, it might be a bad idea because KO is already an international well known company and KO sells its product almost everywhere...so there are not too many opportunities for growth. Even if KO ratios and metrics says it's a good time to buy because it's undervalued, people might not invest on it because KO doesn't have the same potential to grow as 10 years ago. The best chance to grow is demographics. You are better off either buying ETFs monthly for many years (10 minimum) OR find small-cap and mid-cap companies that have the potential to grow plus their ratios indicate they might be undervalued. If you want your investment to work remember this: stock price growth is nothing more than You might ask yourself. What is your investment profile? Agressive? Speculative? Income? Dividends? Capital preservation? If you want something not too risky: ETFs. And not waste too much time. If you want to get more returns, you have to take more risks: find small-cap and mid-companies that are worth. I hope I helped you!
"Some companies issue multiple classes of shares.  Each share may have different ratios applied to ownership rights and voting rights.  Some shares classes are not traded on any exchange at all.  Some share classes have limited or no voting rights.   Voting rights ratios are not used when calculating market cap but the market typically puts a premium on shares with voting rights. Total market cap must include ALL classes of shares, listed or not, weighted according to thee ratios involved in the company's ownership structure.  Some are 1:1, but in the case of Berkshire Hathaway, Class B shares are set at an ownership level of 1/1500 of the Class A shares. In terms of Alphabet Inc, the following classes of shares exist as at 4 Dec 2015: When determining market cap, you should also be mindful of other classes of securities issued by the company, such as convertible debt instruments and stock options.  This is usually referred to as ""Fully Diluted"" assuming all such instruments are converted." "They do but you're missing some calculations needed to gain an understanding. Intro To Stock Index Weighting Methods notes in part: Market cap is the most common weighting method used by an index.   Market cap or market capitalization is the standard way to measure the   size of the company. You might have heard of large, mid, or small cap   stocks? Large cap stocks carry a higher weighting in this index. And   most of the major indices, like the S&P 500, use the market cap   weighting method. Stocks are weighted by the proportion of their market cap to the total   market cap of all the stocks in the index. As a stock’s price and   market cap rises, it gains a bigger weighting in the index. In turn   the opposite, lower stock price and market cap, pushes its weighting   down in the index.  Pros Proponents argue that large companies have a bigger effect on the   economy and are more widely owned. So they should have a bigger   representation when measuring the performance of the market. Which is   true. Cons It doesn’t make sense as an investment strategy. According to a market   cap weighted index, investors would buy more of a stock as its price   rises and sell the stock as the price falls. This is the exact   opposite of the buy low, sell high mentality investors should use. Eventually, you would have more money in overpriced stocks and less in   underpriced stocks. Yet most index funds follow this weighting method. Thus, there was likely a point in time where the S & P 500's initial sum was equated to a specific value though this is the part you may be missing here. Also, how do you handle when constituents change over time? For example, suppose in the S & P 500 that a $100,000,000 company is taken out and replaced with a $10,000,000,000 company that shouldn't suddenly make the index jump by a bunch of points because the underlying security was swapped or would you be cool with there being jumps when companies change or shares outstanding are rebalanced? Consider carefully how you answer that question. In terms of histories, Dow Jones Industrial Average and S & P 500 Index would be covered on Wikipedia where from the latter link: The ""Composite Index"",[13] as the S&P 500 was first called when it   introduced its first stock index in 1923, began tracking a small   number of stocks. Three years later in 1926, the Composite Index   expanded to 90 stocks and then in 1957 it expanded to its current   500.[13] Standard & Poor's, a company that doles out financial information and analysis, was founded in 1860 by Henry Varnum Poor. In   1941 Poor's Publishing (Henry Varnum Poor's original company) merged   with Standard Statistics (founded in 1906 as the Standard Statistics   Bureau) and therein assumed the name Standard and Poor's Corporation.   The S&P 500 index in its present form began on March 4, 1957.   Technology has allowed the index to be calculated and disseminated in   real time. The S&P 500 is widely used as a measure of the general   level of stock prices, as it includes both growth stocks and value   stocks. In September 1962, Ultronic Systems Corp. entered into an agreement   with Standard and Poor's. Under the terms of this agreement, Ultronics   computed the S&P 500 Stock Composite Index, the 425 Stock Industrial   Index, the 50 Stock Utility Index, and the 25 Stock Rail Index.   Throughout the market day these statistics were furnished to Standard   & Poor's. In addition, Ultronics also computed and reported the 94 S&P   sub-indexes.[14] There are also articles like Business Insider that have this graphic that may be interesting: S & P changes over the years The makeup of the S&P 500 is constantly changing notes in part: ""In most years 25 to 30 stocks in the S&P 500 are replaced,"" said   David Blitzer, S&P's Chairman of the Index Committee. And while there   are strict guidelines for what companies are added, the final decision   and timing of that decision depends on what's going through the heads   of a handful of people employed by Dow Jones." Equal weighted indexes are not theoretically meant to be less volatile or less risky; they're just a different way to weigh stocks in an index. If you had a problem that hurt small caps more than large caps, an equal weighted index will be hurt more than a market-cap weighted one.  On the other hand, if you consider that second rung companies have come up to replace the top layer, it makes sense to weigh them on par.  History changes on a per-country basis - in India, for instance, the market's so small at the lower-cap end that big money chases only the large caps, which go up more in a liquidity driven move. But in a more secular period (like the last 18 months) we see that smaller caps have outperformed. "As Dheer pointed out, the top ten mega-cap corporations account for a huge part (20%) of your ""S&P 500"" portfolio when weighted proportionally. This is one of the reasons why I have personally avoided the index-fund/etf craze -- I don't really need another mechanism to buy ExxonMobil, IBM and Wal-Mart on my behalf. I like the equal-weight concept -- if I'm investing in a broad sector (Large Cap companies), I want diversification across the entire sector and avoid concentration. The downside to this approach is that there will be more portfolio turnover (and expense), since you're holding more shares of the lower tranches of the index where companies are more apt to churn. (ie. #500 on the index gets replaced by an up and comer). So you're likely to have a higher expense ratio, which matters to many folks." If your gut told you to buy during the depths of '09, your gut might be well-calibrated. The problem is stock market declines during recessions are frequently not that large relative to the average long run return of 9%:  A better strategy might be hold a percentage in equities based upon a probability distribution of historical returns.  This becomes problematic because of changes in the definition of earnings and the recent inflation stability which has encouraged high valuations:  Cash flow has not been as corrupted as earnings now, and might be a better indicator:  This obviously isn't perfect either, but returns can be improved. Since there is no formulaic way yet conventionally available, the optimal primary strategy is still buy & hold which has made the most successful investor frequently one of the richest people on the planet for decades, but this could still be used as an auxiliary for cash management reserves during recessions once retired. It is simply an average of what each analyst covering that stock are recommending, and since they usually only recommend Hold or Buy (rarely Sell), the value will float between Hold and Buy. Not very useful IMHO. I don't know too much about the kelly criterion, but going by the other answers it sounds like it could be quite risky depending how you use it. I have been taught the first thing you do in trading is protect your existing capital and any profits you have made, and for this reason I prefer and use Position Sizing (PS). The concept with PS is that you only risk a small % of your capital on every trade, usually not more than 1%, however if you want to be very aggressive then not more than 2%. I use 1% of my capital for every trade. So if you are trading with an account of $40,000 and your risk R on every trade is 1%, then R = $400. As an example, say you decide to buy a stock at $10 and you work out your initial stop to be at $9.50, then our maximum risk R of $400 is divided by the stop distance of $0.50 to get your PS = $400/$0.50 = 800 shares. If the price then drops after your purchase, your maximum loss (subject to no slippage) would be $400.  If the price moves up you would raise your stop until your potential loss becomes smaller and smaller and then becomes a gain once your stop moves above your initial purchase price. The aim is to make your gains be larger than your losses. So if your average loss is kept to 1R or less then you should aim to get your average gains to 2R, 3R or more. This would be considered a good trading system where you will make regular profits even with a win ratio of 50%. The price-earnings ratio is calculated as the market value per share divided by the earnings per share over the past 12 months. In your example, you state that the company earned $0.35 over the past quarter. That is insufficient to calculate the price-earnings ratio, and probably why the PE is just given as 20. So, if you have transcribed the formula correctly, the calculation given the numbers in your example would be: 0.35 * 4 * 20 = $28.00 As to CVRR, I'm not sure your PE is correct. According to Yahoo, the PE for CVRR is 3.92 at the time of writing, not 10.54. Using the formula above, this would lead to: 2.3 * 4 * 3.92 = $36.06 That stock has a 52-week high of $35.98, so $36.06 is not laughably unrealistic. I'm more than a little dubious of the validity of that formula, however, and urge you not to base your investing decisions on it.