How should I decide whether to buy more shares of a stock when its price drops?
"A key principle of economics is: Sunk costs are irrelevant. You bought the stock at 147 and it has now fallen to 144. That's too bad. This has nothing to do with whether it is wise or foolish to buy shares at 144. The only relevant thing to consider is: Do I expect the stock to go up or down from 144? You have lost $3 per share on the original buy. Buying more shares will not ""reduce your loss"" in any way. Suppose you bought 100 shares at 147. The price then drops to 144. You have lost $3 per share, or $300 total. You buy another 50 more shares at 144. The price stays at 144. So your average purchase price is now (147 x 100 + 144 x 50) / 150 = 146. So I guess you could say that your ""average loss per share"" is now only $2. But it's $2 x 150 shares instead of $3 x 100 shares. You still lost $300. You didn't reduce your loss by a penny. Maybe it made you feel better that you reduced your average loss per share, but this is just an arithmetic game. If you believe that the stock will continue to drop, than buying more shares just means you will lose even more money. Your average loss per share may go down, but you're just multiplying that average by more and more shares. Of course if you believe that the stock is now at an unjustifiably low price and it will likely go back up, then sure, buy. If you buy at 144 and it goes back up to 147, then you'll be making $3 per share on the new shares you purchased. But I repeat, whether or not you buy more shares should have nothing to do with your previous buy. Buy more shares if you think the price will go up from the present price; don't buy more shares if you don't think it will go up. The decision should be exactly the same as if you had never previously bought shares. (I'm assuming here that you are a typical small investor, that you not buying enough shares to have any significant effect on the market, nor that you are in a position to buy enough shares to take control of the company.)" There is no way to find out what future will be if you have only quote from past. In other words, nobody is able to trade history successfully and nobody will be able, ever. Quote's movement is not random. Quote is not price. Because brokerage account is not actual money. Any results in past do not guarantee you anything. Brokerage accounts should only have portions of money which you are ready to loose completely. Example: Investment firms recommended buying falling Enron stocks, even when it collapsed 3 times, then - bankrupt, suddenly. What a surprise!
"Isn't it true that on the ex-dividend date, the price of the stock goes down roughly the amount of the dividend? That is, what you gain in dividend, you lose in price drop. Yes and No. It Depends! Generally stocks move up and down during the market, and become more volatile on some news. So One can't truly measure if the stock has gone down by the extent of dividend as one cannot isolate other factors for what is a normal share movement. There are time when the prices infact moves up. Now would it have moved more if there was no dividend is speculative. Secondly the dividends are very small percentage compared to the shares trading price. Generally even if 100% dividend are announced, they are on the share capital. On share prices dividends would be less than 1%. Hence it becomes more difficult to measure the movement of stock. Note if the dividend is greater than a said percentage, there are rules that give guidelines to factor this in options and other area etc. Lets not mix these exceptions. Why is everyone making a big deal out of the amount that companies pay in dividends then? Why do some people call themselves ""dividend investors""? It doesn't seem to make much sense. There are some set of investors who are passive. i.e. they want to invest in good stock, but don't want to sell it; i.e. more like keep it for long time. At the same time they want some cash potentially to spend; similar to interest received on Bank Deposits. This class of share holders, it makes sense to invest into companies that give dividends, as year on year they keep receiving some money. If they on the other hand has invested into a company that does not give dividends, they would have to sell some units to get the same money back. This is the catch. They have to sell in whole units, there is brokerage, fees, etc, there are tax events. Some countries have taxes that are more friendly to dividends than capital gains. Thus its an individual choice whether to invest into companies that give good dividends or into companies that don't give dividends.  Giving or not giving dividends does not make a company good or bad." "Investopedia explains how a stock split impacts the stock's options: Each option contract is typically in control of 100 shares of an underlying security at a predetermined strike price. To find the new coverage of the option, take the split ratio and multiply by the old coverage (normally 100 shares). To find the new strike price, take the old strike price and divide by the split ratio. Say, for example, you own a call for 100 shares of XYZ with a strike price of $75. Now, if XYZ had a stock split of 2 for 1, then the option would now be for 200 shares with a strike price of $37.50. If, on the other hand, the stock split was 3 for 2, then the option would be for 150 shares with a strike price of $50. So, yes, a 2 for 1 stock split would halve the option strike prices.  Also, in case the Investopedia article isn't clear, after a split the options still control 100 shares per contract. Regarding how a dividend affects option prices, I found an article with a good explanation: As mentioned above, dividends payment could reduce the price of a stock due to reduction of the company's assets. It becomes intuitive to know that if a stock is expected to go down, its call options will drop in extrinsic value while its put options will gain in extrinsic value before it happens. Indeed, dividends deflate the extrinsic value of call options and inflate the extrinsic value of put options weeks or even months before an expected dividend payment.  Extrinsic value of Call Options are deflated due to dividends not only because of an expected reduction in the price of the stock but also due to the fact that call options buyers do not get paid the dividends that the stock buyers do. This makes call options of dividend paying stocks less attractive to own than the stocks itself, thereby depressing its extrinsic value. How much the value of call options drop due to dividends is really a function of its moneyness. In the money call options with high delta would be expected to drop the most on ex-date while out of the money call options with lower delta would be least affected. If a stock is expected to drop by a certain amount, that drop would already have been priced into the extrinsic value of its put options way beforehand. This is what happens to put options of dividend paying stocks. This effect is again a function of options moneyness but this time, in the money put options raise in extrinsic value more than out of the money put options. This is because in the money put options with delta of close to -1 would gain almost dollar or dollar on the drop of a stock. As such, in the money put options would rise in extrinsic value almost as much as the dividend rate itself while out of the money put options may not experience any changes since the dividend effect may not be strong enough to bring the stock down to take those out of the money put options in the money. So, no, a dividend of $1 will not necessarily decrease an option's price by $1 on the ex-dividend date.  It depends on whether it's a call or put option, and whether the option is ""in the money"" or ""out of the money"" and by how much." Ok you're looking at this in a very confusing way. First, as said by CapitalNumb3rs, the dividend yield is the dividends paid in the year as a percent of the stock price. Given this fact then if the stock price moves down and the dividend stays the same then the yield increases. Company's don't usually pay out on a yield basis, that's mostly just a calculation to measure how strong a dividend is. This could mean either A. The stock is underpriced and will rise which will lower the yield to a more normal level or B. the company is not doing as well and eventually the dividends will decrease to a point where the yield again looks more normal.   Second off let's look at it in a more realistic way that still takes into account your assumptions:  **YEAR 1** 1. Instead of assuming buying 35% let's put this into a share amount. Let's say there are 1,000,000 shares so you just bought 350k shares for $700k. You paid a price of $2/share. Let's assume the market decides that's a fair price and it stays that way through the end of year 1. This gives us a market capitalization of $2 million.  2. The dividend paid out at year 1 is $60k so you could calculate on a per share basis which would be a dividend of $60k / 1 million shares or a $0.06 dividend per share. Our stock price is still at $2.00 so our yield comes out to $0.06 / $2.00 or 3.0%  **YEAR 2** Assuming no additional shares issued there are still a total of 1 million shares outstanding. You owned 350k and now want to purchase another 50k (5% of outstanding share float). The market price you are able to purchase the 50k shares at has now changed which means that share price is now valued at $1.50 / share. We have a dividend paid out at $100k, which comes out to a dividend per share of $0.10. We have a share value of $1.50 and the $0.10 dividend per share giving us a new yield of 6.66%.   **CONCLUSION:** There are many factors that can cause a company's stock price to fluctuate, some of it is hype based but some of it is a result of material changes. In your case the stock went down 25%. In most scenarios where a stock would have that much decline it would likely either not have been paying a dividend in the first place or would maybe not be paying one for much longer. Most companies that pay dividends are larger and more mature companies with a steady, healthy and predictable cash flow. Also most companies that are that size would not trade a stock under $3.00, I know this is just an example but the scenario is definitely a bit extreme in terms of the price drop and dividend increase. Again the yield is just a calculation that depends on the dividend that is usually planned in advance and the stock price that can fluctuate for many reasons. I hope this made everything more clear and let me know if you have any other questions. Using any simulator will never be exactly the same as real trading.  One reason is that a simulator will always execute your trades at the exact price you want, but that may not always happen in real life. For example, if you place a limit order to buy 1000 shares of a stock at 10.50, and the price drops down to exactly 10.50, then the simulator will execute your trade and you will have 1000 shares at 10.50.  But in real life, the price of the stock may drop to 10.50, but other people may have buy orders ahead of you.  If the price of the stock drops to 10.50 but then starts going up again, you may not get all the shares that you wanted (or you may not even get any shares at all) due to the fact that people were ahead of you. In real trading there is also slippage, which you don't see in a simulator.  For example, if you have a stop order to sell 1000 shares of a stock if it drops to 7.50, then the simulator will sell all 1000 shares at 7.50 if the price drops to 7.50.  But in real trading, if the price drops to 7.50, then you may not be able to sell all 1000 shares at 7.50 if there's not enough liquidity or the market is moving very fast.  You may end up selling 100 shares at 7.50, 100 shares at 7.49, 100 shares at 7.48, 50 shares at 7.47, 50 shares at 7.46, 200 shares at 7.45, and 400 shares at 7.44. Another thing is that you don't experience the emotional aspect of trading with a simulator.  If you buy a stock in a simulator and it goes down, it's not real money, so you may be more willing to hold it and wait for it to come back up.  But if you are trading real money and the stock goes down, you may not be so willing to hold if it goes down.  You may be more apt to sell the stock for a small loss before the loss gets too big. You want to buy when the stock market is at an all-time low for that day. Unfortunately, you don't know the lowest time until the end of the day, and then you, uh can't buy the stock... Now the stock market is not random, but for your case, we can say that effectively, it is. So, when should you buy the stock to hopefully get the lowest price for the day? You should wait for 37% of the day, and then buy when it is lower than it has been for all of that day. Here is a quick example (with fake data): We have 18 points, and 37% of 18 is close to 7. So we discard the first 7 points - and just remember the lowest of those 7. We bear in mind that the lowest for the first 37% was 5. Now we wait until we find a stock which is lower than 5, and we buy at that point: This system is optimal for buying the stock at the lowest price for the day. Why? We want to find the  best position to stop automatically ignoring. Why 37%? We know the answer to P(Being in position n) - it's 1/N as there are N toilets, and we can select just 1. Now, what is the chance we select them, given we're in position n? The chance of selecting any of the toilets from 0 to K is 0 - remember we're never going to buy then. So let's move on to the toilets from K+1 and onwards. If K+1 is better than all before it, we have this: But, K+1 might not be the best price from all past and future prices. Maybe K+2 is better. Let's look at K+2 For K+2 we have K/K+1, for K+3 we have K/K+2... So we have: This is a close approximation of the area under 1/x - especially as x → ∞   So 0 + 0 + ... + (K/N) x (1/K + 1/K+1 + 1/K+2 ... + 1/N-1) ≈ (K/N) x ln(N/K) and so P(K) ≈ (K/N) x ln(N/K) Now to simplify, say that x = K/N We can graph this, and find the maximum point so we know the maximum P(K) - or we can use calculus. Here's the graph:  Here's the calculus: To apply this back to your situation with the stocks, if your stock updates every 30 seconds, and is open between 09:30 and 16:00, we have 6.5 hours = 390 minutes = 780 refreshes. You should keep track of the lowest price for the first 289 refreshes, and then buy your stock on the next best price. Because x = K/N, the chance of you choosing the best price is 37%. However, the chance of you choosing better than the average stock is above 50% for the day. Remember, this method just tries to mean you don't loose money within the day - if you want to try to minimise losses within the whole trading period, you should scale this up, so you wait 37% of the trading period (e.g. 37% of 3 months) and then select. The maths is taken from Numberphile - Mathematical Way to Choose a Toilet. Finally, one way to lose money a little slower and do some good is with Kiva.org - giving loans to people is developing countries. It's like a bank account with a -1% interest - which is only 1% lower than a lot of banks, and you do some good. I have no affiliation with them. From your question, I am guessing that you are intending to have stoploss buy order. is the stoploss order is also a buy order ?  As you also said, you seems to limit your losses, I am again guessing that you have short position of the stock, to which you are intending to place a buy limit order and buy stoploss order (stoploss helps when when the price tanks). And also I sense that you intend to place buy limit order at the price below the market price. is that the situation?  If you place two independent orders (one limit buy and one stoploss buy). Please remember that there will be situation where two orders also get executed due to market movements. Add more details to the questions. it helps to understand the situation and others can provide a strategic solution. "If the stock market dropped 30%-40% next month, providing you with a rare opportunity to buy stocks at a deep discount, wouldn't you want to have some of your assets in investments other than stocks? If you don't otherwise have piles of new cash to throw into the market when it significantly tanks, then having some of your portfolio invested elsewhere will enable you to back up the proverbial truck and load up on more stocks while they are on sale. I'm not advocating active market timing. Rather, the way that long-term investors capitalize on such opportunities is by choosing a portfolio asset allocation that includes some percentage of safer assets (e.g. cash, short term bonds, etc.), permitting the investor to rebalance the portfolio periodically back to target allocations (e.g. 80% stocks, 20% bonds.) When rebalancing would have you buy stocks, it's usually because they are on sale. Similarly, when rebalancing would have you sell stocks, it's usually because they are overpriced. So, don't consider ""safer investments"" strictly as a way to reduce your risk. Rather, they can give you the means to take advantage of market drops, rather than just riding it out when you are already 100% invested in stocks. I could say a lot more about diversification and risk reduction, but there are plenty of other great questions on the site that you can look through instead." Have the reasons you originally purchased the stock changed? Is the company still sound? Does the company have a new competitor? Has the company changed the way they operate? If the company is the same, except for stock price, why would you change your mind on the company now? ESPECIALLY if the company has not changed, -- but only other people's PERCEPTION of the company, then your original reasons for buying it are still valid.  In fact, if you are not a day-trader, then this COMPANY JUST WENT ON SALE and you should buy more. If you are a day trader, then you do care about the herd's perception of value (not true value) and you should sell. DAY TRADER = SELL BUY AND HOLD (WITH INTELLIGENT RESEARCH) = BUY MORE