If throwing good money after bad is generally a bad idea, is throwing more money after good Ok?
"The response to this question will be different depending which of the investment philosophies you are using.  Value investors look at the situation the company is in and try to determine what the company is worth and what it will be worth in the future. Then they look at the current stock price and decide whether or not the stock is priced at a good deal or not. If the stock price is priced lower than they believe the company is worth, they would want to buy stock, and if the price rises above what they believe to be the true value, they would sell. These types of investors are not looking at the history or trend of what the price has done in the past, only what the current price is and where they believe the price should be in the future.  Technical analysis investors do something different. It is their belief that as stock prices go up and down, they generally follow patterns. By looking at a chart of what a stock price has been in the past, they try to predict where it is headed, and buy or sell based on that prediction.  In general, value investors are longer-term investors, and technical analysis investors are short-term investors.  The advice you are considering makes a lot of sense if you are using technical analysis. If you have a stock that is trending down, your strategy probably tells you to sell; buying more in the hopes of turning things around would be seen as a mistake. It is like the gambler in Vegas who keeps playing a game he is losing, hoping that his luck changes.  However, for the value investor, the historical price of a stock, and even the amount you currently have gained or lost in the stock, are essentially ignored. All that matters is whether or not the stock price is above or below the true value determined by the investor. For him, if the stock price falls and he believes the company still has a high value, it could be a signal to buy more. The above advice doesn't really apply for them.  Many investors don't follow either of these strategies. They believe that it is too difficult and risky to try to predict the future price of an individual stock. Instead, they invest in many companies all at once using index mutual funds, believing that the stock market as a whole always heads up over a long time frame. Those investors don't care at all if the prices of stock are going up or down. They simply keep investing each month, and hold until they have another use for the money. The above advice isn't useful for them at all.  No matter which kind of investing you are doing, the most important thing is to pick a strategy you believe in and follow the plan without emotion. Emotions can cause investors to make mistakes and start buying when their strategy tells them to sell.  Instead of trying to follow fortune cookie advice like ""Don't throw good money after bad,"" choose an investment strategy, make a plan, test it, and follow it, cautiously (after all, it may be a bad plan). For what it is worth, I am the third type of investor listed above. I don't buy individual stocks, and I don't look at the stock prices when investing more each month. Your description of your own strategy as ""buy and hold"" suggests you might prefer the same approach." "I have heard that investing more money into an investment which has   gone down is generally a bad idea*. ""Throwing good money after bad"" so   to speak. Is investing more money into a stock, you already have a stake in,   which has gone up in price; a good idea? Other things being equal, deciding whether to buy more stocks or shares in a company you're already invested in should be made in the same way you would evaluate any investment decision and -- broadly speaking -- should not be influenced by whether an existing holding has gone up or down in value. For instance, given the current price of the stock, prevailing market conditions, and knowledge about the company, if you think there is a reasonable chance that the price will rise in the time-period you are interested in, then you may want to buy (more) stock. If you think there is a reasonable chance the price will fall, then you probably won't want to buy (more) stock. Note: it may be that the past performance of a company is factored into your decision to buy (e.g was a recent downturn merely a ""blip"", and long-term prospects remain good; or have recent steady rises exhausted the potential for growth for the time being). And while this past performance will have played a part in whether any existing holding went up or down in value, it should only be the past performance -- not whether or not you've gained or lost money -- that affects the new decision. For instance: let us suppose (for reasons that seemed valid at the time) you bought your original holding at £10/share, the price has dropped to £2/share, but you (now) believe both prices were/are ""wrong"" and that the ""true price"" should be around £5/share. If you feel there is a good chance of this being achieved then buying shares at £2, anticipating they'll rally to £5, may be sound. But you should be doing this because you think the price will rise to £5, and not because it will offset the loses in your original holding. (You may also want to take stock and evaluate why you thought it a good idea to buy at £10... if you were overly optimistic then, you should probably be asking yourself whether your current decisions (in this or any share) are ""sound""). There is one area where an existing holding does come into play: as both jamesqf and Victor rightly point out, keeping a ""balanced"" portfolio -- without putting ""all your eggs in one basket"" -- is generally sound advice. So when considering the purchase of additional stock in a company you are already invested in, remember to look at the combined total (old and new) when evaluating how the (potential) purchase will affect your overall portfolio." "I have heard that investing more money into an investment which has gone down is generally a bad idea*. ""Throwing good money after bad"" so to speak. This is over simplified statement to explain the concept. What is essentially says is; Say I hold stocks of XYZ; 100 units worth say USD 1000. This has lost me x% [say 50%]. The general tendency is to buy 100 more units in anticipation / hope that the price will go up. This is incorrect.  However on case to case basis, this maybe the right decisions. On a periodic basis [or whenever you want to invest more money]; say you have USD 1000 and did not have the stock of XYZ, will you buy this at current price and outlook of the company. If the answer is Yes, hold the stock [or buy more], if the answer is no sell the stock at current market price and take the loss. The same applies when the price has appreciated. If you have USD 1000; given the current price and future outlook, will you buy the specific stock. If yes, hold the stock [or buy more], if answer is no sell the stock and book profit. Off-course I have not overlaid the various other considerations when buying stocks like diversification, risk profiles of individual stocks / segments, tax implications etc that are also essential even if you decide to buy or sell specific stock." The principle behind the advice to not throw good money after bad is better restated in economics terms: sunk costs are sunk and irrelevant to today's decisions.   Money lost on a stock is sunk and should not affect our decisions today, one way or the other.  Similarly, the stock going up should not affect our decisions today, one way or the other.  Any advice other than this is assuming some kind of mispricing or predictability in the market.  Mispricings in general cannot be reliably identified and stock returns are not normally predictable. The only valid (efficient markets) reason I know of to allow money you have lost or made on a stock to affect your decision today is the tax implications (you may want to lock in gains if your tax rate is temporarily low or vice versa). To expand a bit on what TripeHound said in the comment section, past performance is not indicative of future performance, which is why the best advice is to ignore if you already own the stock or not.  If the stock goes down, but you've done your research and think it will come back, then investing more isn't a bad idea. If the stock is doing well and it will continue to do well, then invest more. Treat investing more into a stock you already own as a new investment and do your research.  TL;DR of your question, it's a very case-by-case basis Is investing more money into a stock that you already have a stake, in which has gone up in price a good idea? What you describe here is a good idea when the stock keeps up-trending. The way to do it is say you have originally bought $1000 worth of shares, then the next purchase you buy $500 worth, then $250 worth. It is called pyramiding into your trades. However, this system would not be the best with simply a buy and hold when you keep holding even if the price starts freefalling. You would need to have a trailing stop loss on your initial trade, and then as you buy each additional trade your trailing stop loss would incorporate the additional trade and move to a level where if you get stopped out you will make an overall profit. With each additional trade your trailing stop will move higher and higher for higher protected profits. The whole point behind pyramid trading is to keep buying more of a stock that keeps performing well to increase your profits. However, each additional purchase is half the previous one so that you don't eat too much into existing profits (in the case of the uptrend reversing) and so as to not overcapitalise on the one stock. So you are using part of your existing profits in an attempt to make more profits.
"You should see ""Restaurant Impossible"" on TV, shows exactly how you'll end up if you take this direction. Bottom line - yes, it is usually bad. There's a race condition there in the hiding: you either learn the ropes as you go, or you run out of money and go bankrupt, whichever comes first. My personal experience shows that things that seem simple from the outside may become very very complex once you're actually inside. As an engineer I know perfectly well that the devil is in the details. As an investor I know not to step into something I don't know how to step out of. If someone sells something - you should give a thought as to why they're selling. Is the restaurant making money? What's the cashflow? Are there underlying issues? What are the development plans in the neighborhood for the foreseeable future? What's the clientele, and what are the trends? What's with the competition? Can you answer these questions? If not - you're not in a position to enter the business." "I would undoubtedly sell the investments if they are positive, maybe even a little negative.  That's what non-retirement investments are for, building wealth to spend, give, etc. Flipping things may put it in perspective.  Would you borrow money or liquidate your emergency fund in order to invest in mutual funds? If you can completely ignore risk then this MAY make sense. Let's say if you could borrow money at 3.75% and had a ""guaranteed"" investment return of 7.5% and a ""guaranteed"" source of income (job). But mutual funds (stocks, bonds) aren't even guaranteed to make money and they most definitely can lose and lose big. Also, I hope your job isn't in any way tied to the oil industry. On the other hand, if you take a loan and fall on hard times you can liquidate your mutual funds to get out of the bind, but you are at the mercy of the market and the worth of your investments at that point.  So it may come down to whether you want to choose when to spend your investments, when they are up or at some future date when they may be worth much less (or much more)." "In general, there should be a ""liquidity premium"" which means that less-liquid stocks should be cheaper. That's because to buy such a stock, you should demand a higher rate of return to compensate for the liquidity risk (the possibility that you won't be able to sell easily). Lower initial price = higher eventual rate of return. That's what's meant when Investopedia says the security would be cheaper (on average). Is liquidity good? It depends. Here's what illiquidity is. Imagine you own a rare piece of art. Say there are 10 people in the world who collect this type of art, and would appreciate what you own. That's an illiquid asset, because when you want to sell, maybe those 10 people aren't buying - maybe they don't want your particular piece, or they all happen to be short on funds. Or maybe worse, only one of them is buying, so they have all the negotiating leverage. You'll have to lower your price if you're really in a hurry to sell. Maybe if you lower your price enough, you can get one of the 10 buyers interested, even if none were initially. An illiquid asset is bad for sellers. Illiquid means there aren't enough buyers for you to get a bidding war going at the time of your choosing. You'll potentially have to wait around for buyers to turn up, or for a stock, maybe you'd have to sell a little bit at a time as buyers want the shares. Illiquid can be bad for buyers, too, if the buyer is for some reason in a hurry; maybe nobody is selling at any given time. But, usually buyers don't have to be in a hurry. An exception may be if you short sell something illiquid (brokers often won't let you do this, btw). In that case you could be a forced buyer and this could be very bad on an illiquid security. If there are only one or two sellers out there, they now have the negotiating leverage and they can ask whatever price they want. Illiquidity is very bad when mixed with margin or short sales because of the potential for forced trades at inopportune times. There are plenty of obscure penny stocks where there might be only one or two trades per day, or fewer. The spread is going to be high on these because the bids at a given time will just be lowball offers from buyers who aren't really all that interested, unless you want to give your stock away, in which case they'll take it. And the asks are going to be from sellers who want to get a decent price, but maybe there aren't really any buyers willing to pay, so the ask is just sitting there with no takers. The bids and asks may be limit orders that have been sitting open for 3 weeks and forgotten about. Contrast with a liquid asset. For example, a popular-model used car in good condition would be a lot more liquid than a rare piece of art, though not nearly as liquid as most stocks. You can probably find several people that want to buy it living nearby, and you're not going to have to drop the price to get a buyer to show up. You might even get those buyers in a bidding war. From illiquid penny stocks, there's a continuum all the way up to the most heavily-traded stocks such as those in the S&P500. With these at a given moment there will be thousands of buyers and sellers, so the spread is going to close down to nearly zero. If you think about it, just statistically, if there are thousands of bids and thousands of asks, then the closest bid-ask pair is going to be close together. That's a narrow spread. While if there are 3 bids and 2 asks on some illiquid penny stock, they might be dollars away from each other, and the number of shares desired might not match up. You can see how liquidity is good in some situations and not in others. An illiquid asset gives you more opportunity to get a good deal because there aren't a lot of other buyers and sellers around and there's some opportunity to ""negotiate"" within the wide spread. For some assets maybe you can literally negotiate by talking to the other party, though obviously not when trading stocks on an exchange. But an illiquid asset also means you might get a bad deal, especially if you need to sell quickly and the only buyers around are making lowball offers. So the time to buy illiquid assets is when you can take your time on both buying and selling, and will have no reason for a forced trade on a particular timeline. This usually means no debt is involved, since creditors (including your margin broker) can force you to trade. It also means you don't need to spend the money anytime soon, since if you suddenly needed the money you'd have a forced trade on your hands. If you have the time, then you put a price out there that's very good for you, and you wait for someone to show up and give you that price - this is how you get a good deal. One more note, another use of the term liquid is to refer to assets with low or zero volatility, such as money market funds. An asset with a lot of volatility around its intrinsic or true value is effectively illiquid even if there's high trade volume, in that any given point in time might not be a good time to sell, because the price isn't at the right level. Anyway, the general definition of a liquid investment is one that you'd be comfortable cashing out of at a moment's notice. In this sense, most stocks are not all that liquid, despite high trading volume. In different contexts people may use ""liquid"" in this sense or to mean a low bid-ask spread." "People have lost money buying houses in good to great neighborhoods.  It's a pretty large red flag that you state this so clearly ""the neighborhood is pretty bad."" I'd rather buy a bad house in a great neighborhood, and spend my weekends fixing it up, turning sweat equity into real equity. A two year bet? I'd pass.  Close to the school, high demand area, and my answer might change.  (And, ""welcome, stranger"")" I think it may be best to take everything you're asking line-by-line. Once you buy stocks on X day of the month, the chances of stocks never actually going above and beyond your point of value on the chart are close to none. This is not true. Companies can go out of business, or take a major hit and never recover.  Take Volkswagen for example, in 2015 due to a scandal they were involved in, their stocks went downhill. Now their stocks are starting to rise again. The investors goal is not to wait as long as necessary to make a profit on every stock purchase, but to make the largest profit possible in the shortest time possible. Sometimes this means selling a stock before it recovers (if it ever does). I think the problem with most buyers is that they desire the most gain they can possibly have. However, that is very risky. This can be true. Every investor needs to gauge the risk they're willing to take and high-gain investments are riskier.  Therefore, it's better to be winning [small/medium] amounts of money (~)100% of the time than [any] amount of money <~25%. Safer investments do tend to yield more consistent returns, but this doesn't mean that every investor should aim for low-yield investments. Again, this is driven by the investor's risk tolerance. To conclude, profitable companies' stock tends to increase over time and less aggressive investments are safer, but it is possible to lose from any stock investment. "Insofar as a 52 week high indicates a peak, yes.  However, the truth is that ""buying low and selling high"" means ""Act a Fool!"" You see, when you buy low, you are perceived to be buying total garbage - throwing your money away and conversely when selling high you are perceived to be a total idiot - selling a winner.  That's how people will see you when you are in fact buying low and/or selling high, right?  It's those people that (mis)value the asset, right?  An asset is worth what the people will pay for it, right? ...And don't forget that holding a loser is MUCH easier than holding a winner. Good luck!" "no way -- he suggests that if you don't have an edge, no one needs to play the game. He doesn't like the idea of a ""lesser bad"" way to invest (MPT).   If you do decide to get involved in investing, then it's about absolute performance, not relative. He believes that the whole relative performance thing -- beating some arbitrary benchmark -- is just an artificial construct." "If i do this, I would assume I have an equal probability to make a profit or a loss. The ""random walk""/EMH theory that you are assuming is debatable. Among many arguments against EMH, one of the more relevant ones is that there are actually winning trading strategies (e.g. momentum models in trending markets) which invalidates EMH.  Can I also assume that probabilistically speaking, a trader cannot do worst than random? Say, if I had to guess the roll of a dice, my chance of being correct can't be less than 16.667%. It's only true if the market is truly an independent stochastic process. As mentioned above, there are empirical evidences suggesting that it's not.  is it right to say then that it's equally difficult to purposely make a loss then it is to purposely make a profit?  The ability to profit is more than just being able to make a right call on which direction the market will be going. Even beginners can have a >50% chance of getting on the right side of the trades. It's the position management that kills most of the PnL." "I think you're confusing risk analysis (that is what you quoted as ""Taleb Distribution"") with arguments against taking risks altogether. You need to understand that not taking a risk - is by itself a risk. You can lose money by not investing it, because of the very same Taleb Distribution: an unpredictable catastrophic event. Take an example of keeping cash in your house and not investing it anywhere. In the 1998 default of the Russian Federation, people lost money by not investing it. Why? Because had they invested the money - they would have the investments/properties, but since they only had cash - it became worthless overnight. There's no argument for or against investing on its own. The arguments are always related to the investment goals and the risk analysis. You're looking for something that doesn't exist." You question is very hard to answer as it is tough to put a value on how much bad your added investment in evil companies would cause and also how much value the charities add.  However, there has been a bunch of really good work on socially responsible investing in general.  This paper might be too technical for some but the conclusion section is very readable and clear. The big worry about socially responsible investing from a financial standpoint is that it will lower returns in the long run.  The paper above and others show fairly clearly that as long as you only exclude a few classes of stocks and still have a fairly broad base that the expected returns are similar.  The main issue though is some socially responsible funds have much higher fees. So the usual advice applies, do your research to make sure your investments are well diversified and have low fees.   As long as the index is fairly broad you can consider the difference between the fees on the socially responsible index and investing in a more common index as the long run cost.  Then you can balance that cost and having more money for charity against the benefits of not investing in evil companies. "If you are already invested in a particular stock, I like JoeTaxpayer's answer. Think about it as if you are re-buying the stocks you own every day you decide to keep them and don't set emotional anchor points about what you paid for them or what they might be worth tomorrow. These lead to two major logical fallacies that investor's commonly fall prey to, Loss Aversion and Sunk Cost, both of which can be bad for your portfolio in the long run. To avert these natural tendencies, I suggest having a game plan before you purchase a stock based on on your investment goals for that stock. For example a combination of one or more of the following: I'm investing for the long term and I expect this stock to appreciate and will hold it until (specific event/time) at which point I will (sell it all/sell it gradually over a fixed time period) right around the time I need the money. I'm going to bail on this stock if it falls more than X % from my purchase price. I'm going to cash out (all/half/some) of this investment if it gains more than x % from my purchase price to lock in my returns. The important thing is to arrive at a strategy before you are invested and are likely to be more emotional than rational.  Otherwise, it can be very hard to sell a ""hot"" stock that has suddenly jumped in price 25% because ""it has momentum"" (gambler's fallacy). Conversely it can be hard to sell a stock when it drops by 25% because ""I know it will bounce back eventually"" (Sunk Cost/Loss Aversion Fallacy).  Also, remember that there is opportunity cost from sticking with a losing investment because your brain is saying ""I really haven't lost money until I give up and sell it."" When logically you should be thinking, ""If I move my money to a more promising investment I could get a better return than I am likely to on what I'm holding.""" "Forecasts of stock market direction are not reliable, so you shouldn't be putting much weight on them.  Long term, you can expect to do better in stocks, but obtaining this better expected return has the danger of ""buying in"" to the market at a particularly bad moment, leading to a substantially lower return.  So mitigate that risk while moving in a big piece of cash by ""dollar cost averaging"".  An example would be to divide your cash hoard (conceptually) into say six pieces, and invest each piece in the index fund two months apart.  After a year you will have invested the whole sum at about the average of the index for the year." "It's not necessarily bad but it can cause the stock price to become a lot more volatile. Depends on which side of the bet you're on ;) Suppose a hedge fund manager thinks a company is poorly run. He may buy a ton of shares so that he can get rid of the current CEO and replace it with his/her own. For the hedge fund and others long on the stock, this is good. Those who are trading options or using some short-term strategies could get screwed because of the sudden volatility.  My next point is related to the above. What is the intrinsic value of a stock? The current price of a stock is the equilibrium of all investor's perception of the stock's value. Professionals make up a value for a stock using models such as DCF. Once they do so they trade based on what they believe the value of the stock is. You might calculate a stock is worth 70 and I believe it's 80 so the stock price is going to fluctuate a bit but it should keep within that range (assuming we're the only investors). Then comes a hedge fund manager, say Carl Icahn, and discloses a stake in our stock. ""Wow, the stock must be really valuable!"" Everyone starts buying this stock so up it goes to 90, simply because the guy who seems to know what he's doing bought it. The point here is that now it's not trading based on intrinsic value, now it's purely psychological. Ie. it's now a momentum stock, which you have no idea when it'll crash. Look at Tesla, Netflix, or just google momentum stocks. All the big crashes in stock prices happen when these big funds unload their stocks. A surge in supply will cut the price. The problem is you can't predict when some fund manager will decide to sell some stake of his.  Tying everything together is liquidity. The more liquid a stock is, the easier it is to obtain and the less volatile it is. The more people playing the game, with not too big shares of stock, the faster the price will converge to some equilibrium and with less volatility. Institutional investors take away liquidity." The type of day trading you have described is a form of gambling.  As with any type of gambling, sometimes you win.  Doesn't mean you are good at it or will win next time. As long as you clearly understand that you are doing it for fun, I think your current strategy is fine.  If bankruptcy is on the table, you need to stop now. So far we have a case for yes and no.  I believe the correct answer is... maybe. You mention that most of your expenses are in dollars which is definitely correct, but there is an important complication that I will try to simplify greatly here.  Many of the goods you buy are priced on the international market (a good example is oil) or are made from combinations of these goods.  When the dollar is strong the price of oil is low but when the dollar is weak the price of oil is high. However, when you buy stuff like services (think a back massage) then you pay the person in dollars and the person you are paying just wants dollars so the strength of the dollar doesn't really matter. Most people's expenses are a mix of things that are priced internationally and locally with a bias toward local expenses.  If they also have a mix of investments some of which are international and depend on the strength of the dollar and some are domestic and do not, then they don't have to worry much about the strength/weakness of the dollar later when they sell their investments and buy what they want.  If the dollar is weak than the international goods will be more expensive, but at the same time international part of their portfolio will be worth more. If you plan on retiring in a different country or have 100% of your investments in emerging market stocks than it is worth thinking about either currency hedging or changing your investment mix.  However, for many people a good mix of domestic and international investments covers much of the risk that their currency will weaken while offering the benefits of diversification.  The best part is you don't need to guess if the dollar will get stronger or weaker. tl;dr: If you want your portfolio to not depend on currency moves then hedge.  If you want your retirement to not depend on currency moves then have a good mix of local and unhedged international investments.