Can I profit from anticipating a drop in value?
To expand on the comment made by @NateEldredge, you're looking to take a short position.  A short position essentially functions as follows:  Here's the rub: you have unlimited loss potential.  Maybe you borrow a share and sell it at $10.  Maybe in a month you still haven't closed the position and now the share is trading at $1,000.  The share lender comes calling for their share and you have to close the position at $1,000 for a loss of $990.  Now what if it was $1,000,000 per share, etc. To avoid this unlimited loss risk, you can instead buy a put option contract.  In this situation you buy a contract that will expire at some point in the future for the right to sell a share of stock for $x.  You get to put that share on to someone else. If the underlying stock price were to instead rise above the put's exercise price, the put will expire worthless — but your loss is limited to the premium paid to acquire the put option contract. There are all sorts of advanced options trades sometimes including taking a short or long position in a security.  It's generally not advisable to undertake these sorts of trades until you're very comfortable with the mechanics of the contracts.  It's definitely not advisable to take an unhedged short position, either by borrowing someone else's share(s) to sell or selling an option (when you sell the option you take the risk), because of the unlimited loss potential described above. Purchasing an option to sell the stock is probably the safest bet. This gives you reasonable leverage, and your risk is limited to the cost of the option. Say the stock currently sells for $100 per share. You think it will drop to $80 per share in the next two weeks and the market thinks the price will be stable. Now, consider an option to sell one share of that stock for $95 any time within the next two weeks. The market would consider that option nearly worthless, since in all likelihood, you would lose out by exercising it (since you could just sell the share on the market for a price expected to be higher than that). You might be able to acquire that option for $5. Now, say you're right and within two weeks, the price drops to $80. Now you can purchase a share for $80, exercise the option to sell it for $95, and pocket $15. That would make you a $10 profit on a $5 investment. If you're wrong, you just let the option lapse and are out $5. No problem. In reality, you would buy a number of such options. And you wouldn't actually buy a share and exercise the option, you would just sell the option back to its issuer for $15. "To summarize, there are three basic ways: (3) is the truly dangerous one. If there is a lot of short interest in a stock, but for some reason the stock goes up, suddenly a lot of people will be scrambling to buy that stock to cover their short position -- which will drive the price up even further, making the problem worse.  Pretty soon, a bunch of smart rich guys will be poor guys who are suddenly very aware that they aren't as smart as they thought they were.  Eight years ago, such a ""short squeeze"", as it's called, made the price of VW quadruple in two days.  You could hear the Heinies howl from Hamburg to Haldenwanger. There are ways to protect yourself, of course.  You can go short but also buy a call at a much higher price, thereby limiting your exposure, a strategy called a ""straddle"", but you also reduce your profit if you guessed right. It comes down to, as it always does, do you want to eat well, or to sleep well?"
When we speak about a product or service, we generally refer to its value. Currency, while neither a product or service, has its own value. As the value of currency goes down, the price of products bought by that currency will go up. You could consider the price of a product or service the value of the product multiplied by the value of the currency. For your first example, we compare two cars, one bought in 1990, and one bought in 2015. Each car has the same features (AC, radio, ABS, etc). We can say that, when these products were new, each had the same value. However, we can deduce that since the 1990 car cost $100, and the 2015 car cost $400, that there has been 75% inflation over 25 years. Comparing prices over time helps identify the inflation (or devaluation of currency) that an economy is experiencing. In regards to your second question, you can say that there was 7% inflation over five years (total). Keep in mind that these are absolute cumulative values. It doesn't mean that there was a 7% increase year over year (that would be 35% inflation over five years), but simply that the absolute value of the dollar has changed 7% over those five years. The sum of the percentages over those five years will be less than 7%, because inflation is measured yearly, but the total cumulative change is 7% from the original value. To put that in perspective, say that you have $100 in 2010, with an expected 7% inflation by 2015, which means that your $100 will be worth $93 in 2015. This means that the yearly inflation would be about 1.5% for five years, resulting in a total of 7% inflation over five years. Note that you still have a hundred dollar bill in your pocket that you've saved for five years, but now that money can buy less product. For example, if you say that $100 buys 50 gallons of gasoline ($2/gallon) in 2010, you will only be able to afford 46.5 gallons with that same bill in 2015 ($2.15/gallon). As you can see, the 7% inflation caused a 7% increase in gasoline prices. In other words, if the value of the car remained the same, its actual price would go up, because the value stayed the same. However, it's more likely that the car's value will decrease significantly in those five years (perhaps as much as 50% or more in some cases), but its price would be higher than it would have been without inflation. If the car's value had dropped 50% (so $50 in original year prices), then it would have a higher price (50 value * 1.07 currency ratio = $53.50). Note that even though its value has decreased by half, its price has not decreased by 50%, because it was hoisted up by inflation. For your final question, the purpose of a loan is so that the loaner will make a profit from the transaction. Consider your prior example where there was 7% inflation over five years. That means that a loan for $100 in 2010 would only be worth $93 in 2015. Interest is how loans combat this loss of value (as well as to earn some profit), so if the loaner expects 7% inflation over five years, they'll charge some higher interest (say 8-10%, or even more), so that when you pay them back on time, they'll come out ahead, or they might use more advanced schemes, like adjustable rates, etc. So, interest rates will naturally be lower when forecasted inflation is lower, and higher when forecasted inflation is higher. The best time to get a loan is when interest rates are low-- if you get locked into a high interest loan and inflation stalls, they will make more money off of you (because the currency has more value), while if inflation skyrockets, your loan will be worth less to loaner. However, they're usually really good about predicting inflation, so it would take an incredible amount of inflation to actually come out on top of a loan. I think the advice Bob is being given is good. Bob shouldn't sell his investments just because their price has gone down. Selling cheap is almost never a good idea. In fact, he should do the opposite: When his investments become cheaper, he should buy more of them, or at least hold on to them. Always remember this rule: Buy low, sell high. This might sound illogical at first, why would someone keep an investment that is losing value? Well, the truth is that Bob doesn't lose or gain any money until he sells. If he holds on to his investments, eventually their value will raise again and offset any temporary losses. But if he sells as soon as his investments go down, he makes the temporary losses permanent. If Bob expects his investments to keep going down in the future, naturally he feels tempted to sell them. But a true investor doesn't try to anticipate what the market will do. Trying to anticipate market fluctuations is speculating, not investing. Quoting Benjamin Graham: The most realistic distinction between the investor and the speculator is found in their attitude toward stock-market movements. The speculator's primary interest lies in anticipating and profiting from market fluctuations. The investor's primary interest lies in acquiring and holding suitable securities at suitable prices. Market movements are important to him in a practical sense, because they alternately create low price levels at which he would be wise to buy and high price levels at which he certainly should refrain from buying and probably would be wise to sell. Assuming that the fund in question is well-managed, I would refrain from selling it until it goes up again. "The textbook answer would be ""assets-liabilities+present discounted value of all future profit"".  A&L is usually simple (if a company has an extra $1m in cash, it's worth $1m more; if it has an extra $1m in debt, it's worth $1m less). If a company with ~0 assets and $50k in profit has a $1m valuation, then that implies that whoever makes that valuation (wants to buy at that price) really believes one of two things - either the future profit will be significantly larger than $50k (say, it's rapidly growing);  or the true worth of assets is much more - say, there's some IP/code/patents/people that have low book value but some other company would pay $1m just to get that. The point is that valuation is subjective since the key numbers in the calculations are not perfectly known by anyone who doesn't have a time machine, you can make estimates but the knowledge to make the estimates varies (some buyers/sellers have extra information), and they can be influenced by those buyers/sellers; e.g. for strategic acquisitions the value of company is significantly changed simply because someone claims they want to acquire it. And, $1m valuation for a company with $500m in profits isn't appropriate - it's appropriate only if the profits are expected to drop to zero within a couple years; a stagnant but stable company with $500m profits would be worth at least $5m and potentially much more." Instead of giving part of their profits back as dividends, management puts it back into the company so the company can grow and produce higher profits. When these companies do well, there is high demand for them as in the long term higher profits equates to a higher share price. So if a company invests in itself to grow its profits higher and higher, one of the main reasons investors will buy the shares, is in the expectation of future capital gains. In fact just because a company pays a dividend, would you still buy it if the share price kept decreasing year after year? Lets put it this way: Company A makes record profits year after year, continually keeps beating market expectations, its share price keeps going up, but it pays no dividend instead reinvests its profits to continually grow the business. Company B pays a dividend instead of reinvesting to grow the business, it has been surprising the market on the downside for a few years now, it has had some profit warnings lately and its share price has consistently been dropping for over a year. Which company would you be interested in buying out of the two? I know I would be interested in buying Company A, and I would definitely stay away from Company B. Company A may or may not pay dividends in the future, but if Company B continues on this path it will soon run out of money to pay dividends. Most market gains are made through capital gains rather than dividends, and most people invest in the hope the shares they buy go up in price over time. Dividends can be one attractant to investors but they are not the only one. You said the decision will be made by EOD. If you've made the decision prior to the market close, I'd execute on the closing price.  If you are trading stocks with any decent volume, I'd not worry about the liquidity.  If your strategy's profits are so small that your gains are significantly impacted by say, the bid/ask spread (a penny or less for liquid stocks) I'd rethink the approach. You'll find the difference between the market open and prior night close is far greater than the normal bid/ask. It depends to some extent on how you interpret the situation, so I think this is the general idea. Say you purchase one share at $50, and soon after, the price moves up, say, to $55. You now have an unrealized profit of $5. Now, you can either sell and realize that profit, or hold on to the position, expecting a further price appreciation. In either case, you will consider the price change from this traded price, which is $55, and not the price you actually bought at. Hence, if the price fell to $52 in the next trade, you have a loss of $3 on your previous profit of $5. This (even though your net P&L is calculated from the initial purchase price of $50), allows you to think in terms of your positions at the latest known prices. This is similar to a Markov process, in the sense that it doesn't matter which route the stock price (and your position's P&L) took to get to the current point; your decision should be based on the current/latest price level. "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." "You can place the orders like you suggested.  This would be useful in a market that is moving quickly where you want to be reasonably sure of execution but don't want the full exposure of a market order.  This won't jump your spot in the queue though in the sense that you won't get ahead of other orders that are ""ready"" for execution just because you have crossed the spread aggressively."