Offsetting capital losses against gains for stocks
The loss for B can be used to write off the gain for A.  You will fill out a schedule 3 with cost base and proceeds of disposition.  This will give you a $0 capital gain for the year and an amount of $5 (50% of the $10 loss) you can carry forward to offset future capital gains.  You can also file a T1-a and carry the losses back up to 3 years if you're so inclined.  It can't be used to offset other income (unless you die). Your C and D trades can't be on income account except for very unusual circumstances.  It's not generally acceptable to the CRA for you to use 2 separate accounting methods.  There are some intricacies but you should probably just use capital gains.   There is one caveat that if you do short sales of Canadian listed securities, they will be on income account unless you fill out form T-123 and elect to have them all treated as capital gains. I just remembered one wrinkle in carrying forward capital losses.  They don't reduce your capital gains anymore, but they reduce your taxable income.  This means your net income won't be reduced and any benefits that are calculated from that (line 236), will not get an increase.
Equal sized gains and losses in alternating years would lead to an   unjust positive tax. On the contrary. If I can take my gains at the long term rate (15%) in even years, but take losses in odd years, up to $3000, or let them offset short term gains at ordinary rate, I've just gamed the system.  What is the purpose of the wash sale rule? Respectfully, we here can do a fine job of explaining how a bit of tax code works. And we can suggest the implication of those code bits. But, I suspect that it's not easy to explain the history of particular rules. For wash sale, the simple intent is to not let someone take a loss without actually selling the stock for a time. You'd be right to say the +/- 30 days is arbitrary.  I'd ask you to keep 2 things in mind if you continue to frequent this board - As a general rule of thumb, age and resiliency of your profession (in terms of high and stable wages) in most cases imply that you have the ABILITY to accept higher than average level of risk by investing in stocks (rather than bonds) in search for capital appreciation (rather than income), simply because you have more time to offset any losses, should you have any, and make capital gains. Dividend yield is mostly sough after by people at or near retirement who need to have some cash inflows but cannot accept high risk of equity investments (hence low risk dividend stocks and greater allocation to bonds). Since you accept passive investment approach, you could consider investing in Target Date Funds (TDFs), which re-allocate assets (roughly, from higher- to lower-risk) gradually as the fund approaches it target, which for you could be your retirement age, or even beyond. Also, why are you so hesitant to consider taking professional advice from a financial adviser? You can keep the cash in your account as long as you want, but you have to pay a tax on what's called capital gains. To quote from Wikipedia: A capital gain is a profit that results from investments into a capital asset, such as stocks, bonds or real estate, which exceeds the purchase price. It is the difference between a higher selling price and a lower purchase price, resulting in a financial gain for the investor.[1] Conversely, a capital loss arises if the proceeds from the sale of a capital asset are less than the purchase price. Thus, buying/selling stock counts as investment income which would be a capital gain/loss. When you are filing taxes, you have to report net capital gain/loss. So you don't pay taxes on an individual stock sale or purchase - you pay tax on the sum of all your transactions.  Note: You do not pay any tax if you have a net capital loss. Taxes are only on capital gains.  The amount you are taxed depends on your tax bracket and your holding period. A short term capital gain is gain on an investment held for less than one year. These gains are taxed at your ordinary income tax rate. A long term capital gain is gain on an investment held for more than one year. These gains are taxed at a special rate: If your income tax rate is 10 or 15%, then long term gains are taxed at 0% i.e. no tax, otherwise the tax rate is 15%. So you're not taxed on specific stock sales - you're taxed on your total gain. There is no tax for a capital loss, and investors sometimes take profits from good investments and take losses from bad investments to lower their total capital gain so they won't be taxed as much. The tax rate is expected to change in 2013, but the current ratios could be extended. Until then, however, the rate is as is.  Of course, this all applies if you live in the United States. Other countries have different measures. Hope it helps!  Wikipedia has a great chart to refer to: http://en.wikipedia.org/wiki/Capital_gains_tax_in_the_United_States. The cap loss can be used to offset future gains or $3000/yr of ordinary income. (I just used up the last of mine from the dot com bubble.) I hope you have future gains that let you use this up quickly.  The IRS debt is separate, and I don't imagine they'll let you use any of the loss to offset it. As always, it can't hurt to ask. Their normal payment plans are for 5 years. $40k/yr is a lot.  Edit - The IRS does negotiate. I recall, from the dot-com bubble, instances where someone exercised stock grants, but kept the shares. Now, they had a $1M gain, but after year end, the stock crashed. They owed tax on that gain, but the loss was in the next tax year, with nothing to offset. These people were 'regular' guys and gals, no background in finance. I understand the IRS looked at these people and made some exceptions. "The process of borrowing shares and selling them is called shorting a stock, or ""going short.""  When you use money to buy shares, it is called ""going long."" In general, your strategy of going long and short in the same stock in the same amounts does not gain you anything.  Let's look at your two scenarios to see why. When you start, LOOT is trading at $20 per share.  You purchased 100 shares for $2000, and you borrowed and sold 100 shares for $2000.  You are both long and short in the stock for $2000.  At this point, you have invested $2000, and you got your $2000 back from the short proceeds.  You own and owe 100 shares. Under scenario A, the price goes up to $30 per share.  Your long shares have gone up in value by $1000.  However, you have lost $1000 on your short shares.  Your short is called, and you return your 100 shares, and have to pay interest.  Under this scenario, after it is all done, you have lost whatever the interest charges are. Under scenario B, the prices goes down to $10 per share.  Your long shares have lost $1000 in value.  However, your short has gained $1000 in value, because you can buy the 100 shares for only $1000 and return them, and you are left with the $1000 out of the $2000 you got when you first sold the shorted shares.  However, because your long shares have lost $1000, you still haven't gained anything.  Here again, you have lost whatever the interest charges are. As explained in the Traders Exclusive article that @RonJohn posted in the comments, there are investors that go long and short on the same stock at the same time.  However, this might be done if the investor believes that the stock will go down in a short-term time frame, but up in the long-term time frame.  The investor might buy and hold for the long term, but go short for a brief time while holding the long position. However, that is not what you are suggesting.  Your proposal makes no prediction on what the stock might do in different periods of time.  You are only attempting to hedge your bets.  And it doesn't work.  A long position and a short position are opposites to each other, and no matter which way the stock moves, you'll lose the same amount with one position that you have gained in the other position.  And you'll be out the interest charges from the borrowed shares every time. With your comment, you have stated that your scenario is that you believe that the stock will go up long term, but you also believe that the stock is at a short-term peak and will drop in the near future.  This, however, doesn't really change things much.  Let's look again at your possible scenarios. You believe that the stock is a long-term buy, but for some reason you are guessing that the stock will drop in the short-term.  Under scenario A, you were incorrect about your short-term guess.  And, although you might have been correct about the long-term prospects, you have missed this gain.  You are out the interest charges, and if you still think the stock is headed up over the long term, you'll need to buy back in at a higher price. Under scenario B, it turns out that you were correct about the short-term drop.  You pocket some cash, but there is no guarantee that the stock will rise anytime soon.  Your investment has lost value, and the gain that you made with your short is still tied up in stocks that are currently down. Your strategy does prevent the possibility of the unlimited loss inherent in the short.  However, it also prevents the possibility of the unlimited gain inherent in the long position.    And this is a shame, since you fundamentally believe that the stock is undervalued and is headed up.  You are sabotaging your long-term gains for a chance at a small short-term gain." "You don't ""deduct"" transaction fees, but they are included in your cost basis and proceeds, which will affect the amount of gain/loss you report. So in your example, the cost basis for each of the two lots is $15 (10$ share price plus $5 broker fee).  Your proceeds for each lot are $27.50 (($30*2 - $5 )/2).  Your gain on each lot is therefore $12.50, and you will report $12.50 in STCG and $12.50 in LTCG in the year you sold the stock (year 3).   As to the other fees, in general yes they are deductible, but there are limits and exceptions, so you would need to consult a tax professional to get a correct answer in your specific situation." &gt;suffering, say, a potential 20% loss for business reasons can be preferable to creating a guaranteed, irreversible 37% loss due to state and federal LTCG taxes.  You don't pay taxes on capital losses...  In fact, you can write them off against future gains. "Offset against taxable gains means that the amount - $25 million in this case - can be used to reduce another sum that the company would otherwise have to pay tax on. Suppose the company had made a profit of $100 million on some other investments. At some point, they are likely to have to pay corporation tax on that amount before being able to distribute it as a cash dividend to shareholders. However if they can offset the $25 million, then they will only have to pay tax on $75 million. This is quite normal as you usually only pay tax on the aggregate of your gains and losses. If corporation tax is about 32% that would explain the claimed saving of approximately $8 million. It sounds like the Plaintiffs want the stock to be sold on the market to get that tax saving. Presumably they believe that distributing it directly would not have the same effect because of the way the tax rules work. I don't know if the Plaintiffs are right or not, but if they are the difference would probably come about due to the stock being treated as a ""realized loss"" in the case where they sell it but not in the case where they distribute it. It's also possible - though this is all very speculative - that if the loss isn't realised when they distribute it directly, then the ""cost basis"" of the shareholders would be the price the company originally paid for the stock, rather than the value at the time they receive it. That in turn could mean a tax advantage for the shareholders."