What is the opposite of a sunk cost? A “sunk gain”?
"It is called ""Opportunity Cost.""   Opportunity cost is the value you lose because of a decision you made.   This is the book definition from Investopedia. The difference in return between a chosen investment and one that is necessarily passed up. Say you invest in a stock and it returns a paltry 2% over the year. In placing your money in the stock, you gave up the opportunity of another investment - say, a risk-free government bond yielding 6%. In this situation, your opportunity costs are 4% (6% - 2%)." "The opposite of a cost is an investment. Buying a car is an expense, usually a sunk cost, whereas purchasing real-estate, e.g. productive farmland, is an investment. (Some investments are wasting assets, as the value decreases over time, but they are still investments with market value, not costs.) ""Sunk cost"" isn't a fallacy. It just means an expenditure that one cannot expect to recoup. The action item is, ""Don't throw good money after bad."" The opposite of a sunk cost is an investment." In the second example you are giving up future  free cash flows in exchange for a capital gain on the original investment. With that respect  the money you will not gain will be the difference of the future cash flows ( net of related costs) minus the net gain on the panel you have sold. The financial result can be considered as the opposite of a sunk cost, that is a cost you have already incurred ( and cannot be recovered)  vs net future gains you are giving up.  In more sophisticated financial terms we are talking about the  benefit-cost ratio:  ( from Investopedia) "The complete opposite of ""sunk cost"" is the term ""unrealized gain""; until you sell it, then it is a ""realized gain"". There is also a term ""paper profit"" to point out the ephemeral nature of some of these unrealized gains." "A ""sunk cost"" is a cost that you have already incurred, and won't get back. The ""sunk cost fallacy,"" as you described, is when you make a bad decision based on your sunk cost.  When you identify a sunk cost, you realize that the money has been spent, and the decision is irreversible.  Future decisions should not take this cost into account.  When you commit the ""sunk cost fallacy,"" you are keeping something that is bad simply because you spent a lot of money on it.  You are failing to identify the correct current value of something based on its high cost to you in the past. The other fallacy you describe, the opposite of the sunk cost fallacy, is when you get rid of something that is good simply because you spent little on it.  As before, you are also failing to correctly identify the correct current value of something, but in this case, you are assigning too little a value based on the low cost in the past.  You could call this a type of ""opportunity cost,"" a loss of future benefits due to a mistake made today.  It seems reasonable to describe this type of fallacy as an ""opportunity cost fallacy.""" "liquid asset A sunk cost may turn out to be a loss or it may make you a profit, but what makes it ""sunk"" is: you can't get it back.  The opposite is a cost that you can later redeem, which makes it ""liquid""."
"-Alain Wertheimer I'm a hobbyist... Most (probably all) of those older items were sold both prior to my establishing the LLC This is a hobby of yours, this is not your business. You purchased all of these goods for your pleasure, not for their future profit. The later items that you bought after your LLC was establish served both purposes (perks of doing what you love).  How should I go about reporting this income for the items I don't have records for how much I purchased them for?  There's nothing you can do. As noted above, these items (if you were to testify in court against the IRS). ""Losses from the sale of personal-use property, such as your home or car, aren't tax deductible."" Source Do I need to indicate 100% of the income because I can't prove that I sold it at a loss? Yes, if you do not have previous records you must claim a 100% capital gain. Source Addition: As JoeTaxpayer has mentioned in the comments, the second source I posted is for stocks and bonds.  So at year begin of 2016, I started selling what I didn't need on eBay and on various forums [January - September]. Because you are not in the business of doing this, you do not need to explain the cost; but you do need to report the income as Gross Income on your 1040. Yes, if you bought a TV three years ago for a $100 and sold it for $50, the IRS would recognize you earning $50.  As these are all personal items, they can not be deducted; regardless of gain or loss. Source Later in the year 2016 (October), I started an LLC (October - December) If these are items that you did not record early in the process of your LLC, then it is reported as a 100% gain as you can not prove any business expenses or costs to acquire associated with it.  Source Refer to above answer.  Refer to above answer.  Conclusion Again, this is a income tax question that is split between business and personal use items. This is not a question of other's assessment of the value of the asset. It is solely based on the instruments of the IRS and their assessment of gains and losses from businesses. As OP does not have the necessary documents to prove otherwise, a cost basis of $0 must be assumed; thus you have a 100% gain on sale." As you mentioned in the title, what you're asking about comes down to volatility.  DCA when purchasing stock is one way of dealing with volatility, but it's only profitable if the financial instrument can be sold higher than your sunk costs.  Issues to be concerned with: Let's suppose you're buying a stock listed on the NYSE called FOO (this is a completely fake example).  Over the last six days, the average value of this stock was exactly $1.00Note 1.  Over six trading days you put $100 per day into this stockNote 2: At market close on January 11th, you have 616 shares of FOO.  You paid $596.29 for it, so your average cost (before fees) is: $596.29 / 616 = $0.97 per share Let's look at this including your trading fees: ($596.29 + $30) / 616 = $1.01 per share. When the market opens on January 12th, the quote on FOO could be anything.  Patents, customer wins, wars, politics, lawsuits, press coverage, etc... could cause the value of FOO to fluctuate.  So, let's just roll with the assumption that past performance is consistent: Selling FOO at $0.80 nets: (616 * $0.80 - $5) - ($596.29 + $30) =  $123.49 Loss Selling FOO at $1.20 nets: (616 * $1.20 - $5) - ($596.29 + $30) =  $107.90 Profit Every day that you keep trading FOO, those numbers get bigger (assuming FOO is a constant value).  Also remember, even if FOO never changes its average value and volatility, your recoverable profits shrink with each transaction because you pay $5 in fees for every one. Speaking from experience, it is very easy to paper trade.  It is a lot harder when you're looking at the ticker all day when FOO has been $0.80 - $0.90 for the past four days (and you're $300 under water on a $1000 portfolio).  Now your mind starts playing nasty games with you. If you decide to try this, let me give you some free advice: Unless you have some research (such as support / resistance information) or data on why FOO is a good buy at this price, let's be honest: you're gambling with DCA, not trading. END NOTES: It could be a sunk cost.  If you buy 5 gallons of vegetable oil it costs $50.  Until you use up all the vegetable oil you dollars are tied up and cannot be spent on popcorn or any other good. So weigh if the convenience is more important than having the cash on hand for other purchases is another factor to consider No, the reinvestment is done as a courtesy. Consider, one can have, say, 100 shares of a $50 stock. A 2% dividend is $100/yr or $25/quarter. It would be a pretty bad deal if brokers charged you even $5 for that trade. When cap gains and dividends are grouped as you suggest, it refers to Mutual Funds. My funds will have a year end dividend and cap gain distribution. In a non-retirement account, one has to pay the tax due, and be sure to add this to your cost basis, as it's money you are effectively adding to your account. It does not mean cap gain the same as when you sell your shares of Apple for a huge gain.  Those check boxes seem to offer you a chance to put all your holding on the same reinvestment plan for div/cap gain. You should also be able to choose one by one what you'd like to do. "I'm just trying to visualize the costs of trading. Say I set up an account to trade something (forex, stock, even bitcoin) and I was going to let a random generator determine when I should buy or sell it. If I do this, I would assume I have an equal probability to make a profit or a loss. Your question is what a mathematician would call an ""ill-posed problem.""  It makes it a challenge to answer.  The short answer is ""no.""  We will have to consider three broad cases for types of assets and two time intervals. Let us start with a very short time interval.  The bid-ask spread covers the anticipated cost to the market maker of holding an asset bought in the market equal to the opportunity costs over the half-life of the holding period.  A consequence of this is that you are nearly guaranteed to lose money if your time interval between trades is less than the half-life of the actual portfolio of the market maker.  To use a dice analogy, imagine having to pay a fee per roll before you can gamble.  You can win, but it will be biased toward losing. Now let us go to the extreme opposite time period, which is that you will buy now and sell one minute before you die.  For stocks, you would have received the dividends plus any stocks you sold from mergers.  Conversely, you would have had to pay the dividends on your short sales and received a gain on every short stock that went bankrupt.  Because you have to pay interest on short sales and dividends passed, you will lose money on a net basis to the market maker.  Maybe you are seeing a pattern here.  The phrase ""market maker"" will come up a lot. Now let us look at currencies.  In the long run, if the current fiat money policy regime holds, you will lose a lot of money.  Deflation is not a big deal under a commodity money regime, but it is a problem under fiat money, so central banks avoid it.  So your long currency holdings will depreciate.  Your short would appreciate, except you have to pay interest on them at a rate greater than the rate of inflation to the market maker. Finally, for commodities, no one will allow perpetual holding of short positions in commodities because people want them delivered.  Because insider knowledge is presumed under the commodities trading laws, a random investor would be at a giant disadvantage similar to what a chess player who played randomly would face against a grand master chess player.  There is a very strong information asymmetry in commodity contracts.  There are people who actually do know how much cotton there is in the world, how much is planted in the ground, and what the demand will be and that knowledge is not shared with the world at large.  You would be fleeced. 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%. A physicist, a con man, a magician and a statistician would tell you that dice rolls and coin tosses are not random.  While we teach ""fair"" coins and ""fair"" dice in introductory college classes to simplify many complex ideas, they also do not exist.  If you want to see a funny version of the dice roll game, watch the 1962 Japanese movie Zatoichi.  It is an action movie, but it begins with a dice game.   Consider adopting a Bayesian perspective on probability as it would be a healthier perspective based on how you are thinking about this problem.  A ""frequency"" approach always assumes the null model is true, which is what you are doing.  Had you tried this will real money, your model would have been falsified, but you still wouldn't know the true model. Yes, you can do much worse than 1/6th of the time.  Even if you are trying to be ""fair,"" you have not accounted for the variance. Extending that logic, then for an inexperienced trader, is it right to   say then that it's equally difficult to purposely make a loss then it   is to purposely make a profit? Because if I can purposely make a loss,   I would purposely just do the opposite of what I'm doing to make a   profit. So in the dice example, if I can somehow lower my chances of   winning below 16.6667%, it means I would simply need to bet on the   other 5 numbers to give myself a better than 83% chance of winning. If the game were ""fair,"" but for things like forex the rules of the game are purposefully changed by the market maker to maximize long-run profitability.  Under US law, forex is not regulated by anything other than common law.  As a result, the market maker can state any price, including prices far from the market, with the intent to make a system used by actors losing systems, such as to trigger margin calls.  The prices quoted by forex dealers in the US move loosely with the global rates, but vary enough that only the dealer should make money systematically.  A fixed strategy would promote loss. You are assuming that only you know the odds and they would let you profit from your 83.33 percentage chance of winning. So then, is the costs of trading from a purely probabilistic point of   view simply the transaction costs? No matter what, my chances cannot   be worse than random and if my trading system has an edge that is   greater than the percentage of the transaction that is transaction   cost, then I am probabilistically likely to make a profit? No, the cost of trading is the opportunity cost of the money.  The transaction costs are explicit costs, but you have ignored the implicit costs of foregone interest and foregone happiness using the money for other things. You will want to be careful here in understanding probability because the distribution of returns for all of these assets lack a first moment and so there cannot be a ""mean return.""  A modal return would be an intellectually more consistent perspective, implying you should use an ""all-or-nothing"" cost function to evaluate your methodology." You buy a share of something for $100.  It goes up by 10% over a year, and you now have $110 in value.  It goes up by 10% next year and you now have $121.  That original $10 increase was compounded even though you're not earning interest because the gains are measured as a percentage.  If, instead, you'd only invested the second year you'd have less value.  Assuming the markets average a positive gain (above inflation) you see greater gains the earlier you're invested. Other metrics like Price/Book Value or Price/Sales can be used to determine if a company has above average valuations and would be classified as growth or below average valuations and be classified as value. Fama and French's 3 Factor model would be one example that was studied a great deal using an inverse of Price/Book I believe. Power Options is one such example of what you seek, not cheap, but one good trade will recover a year's fee.  There's a lot you can do with the stock price alone as most options pricing will follow Black Scholes.  Keep in mind, this is a niche, these questions, while interesting to me, generate little response here.