How does the U.S. wash sale replacement stock rule work?
"From Pub 550: More or less stock bought than sold.   If the number of shares of   substantially identical stock or securities you buy within 30 days   before or after the sale is either more or less than the number of   shares you sold, you must determine the particular shares to which the   wash sale rules apply. You do this by matching the shares bought with   an equal number of the shares sold. Match the shares bought in the   same order that you bought them, beginning with the first shares   bought. The shares or securities so matched are subject to the wash   sale rules. You must match ""beginning with the first shares bought."" If only activity 1 & 4 happened, you'd have bought and sold stock with no wash sale. If you remove activity 1 & 4 from consideration because they are a ""normal"" or non-wash sale transaction, then the Activity 2 or Activity 3 trigger a wash sale. The shares in lot 1 are sold for disallowed loss, so the disallowed basis would be added to shares in lot 2 because lot 2 was purchased before lot 3. (hat tip to user662852 who had much better wording) Second example: Activity 5, 7, and 8 all together would not be a wash sale.   The addition of activity 6 creates a wash sale. The shares in Activity 5 are sold for a disallowed loss in Activity 7 & 8 because of the wash sale triggering purchase in Activity 6.   Activity 6 is where you add the disallowed basis because they are the ""first shares bought"" that cause the wash sale rule to be triggered." "Edited: Pub 550 says 30 days before or after so the example is ok - but still a gain by average share basis.  On sale your basis is likely defaulted to ""average price"" (in the example 9.67 so there was a gain selling at 10), but can be named shares at your election to your brokerage,  and supported by record keeping. A Pub 550 wash might be buy 2000 @ 10 with basis 20000, sell 1000 @9 (nominally a loss of 1000 for now and remaining basis 10000), buy 1000 @ 8 within 30 days.   Because of the wash sale rule the basis is 10000+8000 paid + 1000 disallowed loss from wash sale with a final position of 2000 shares at 19000 basis.  I think I have the link at the example:  http://www.irs.gov/publications/p550/ch04.html#en_US_2014_publink100010601"
&gt; stock funds that Rep. Paul does own are all “short,” or make bets against, U.S. stocks. **One is a “double inverse” fund**  Unless he's actually shorting a 2x bull ETF, he's losing money (regardless of how the benchmark is doing) Honestly, 10 wash trades is next to nothing.  I run a small automated trading firm and I get maybe 20-30 wash trades per quarter.  You get fined for them but it's not a big deal, preventing wash trades can be pretty hard and sometimes it's entirely out of your control.  Canada has much stricter rules about wash trading, the U.S. has more lenient rules on them, and in Europe you can wash trade all you want because honestly it doesn't make much of a difference.  Anyhow, just trying to give some perspective that 10 instances of wash trading is not unusual/uncommon, won't have any market impact one way or another, and often happens by accident.  If anything wash trades are just a pain in the ass, you end up paying transaction costs for nothing. Great question! It can be a confusing for sure -- but here's a great example I've adapted to your scenario: As a Day Trader, you buy 100 shares of LMNO at $100, then after a large drop the same day, you sell all 10 shares at $90 for a loss of $1,000. Later in the afternoon, you bought another 100 shares at $92 and resold them an hour later at $97 (a $500 profit), closing out your position for the day. The second trade had a profit of $500, so you had a net loss of $500 (the $1,000 loss plus the $500 profit).  Here’s how this works out tax-wise: The IRS first disallows the $1,000 loss and lets you show only a profit of $500 for the first trade (since it was a wash). But it lets you add the $1,000 loss to the basis of your replacement shares. So instead of spending $9,200 (100 shares times $92), for tax purposes, you spent $10,200 ($9,200 plus $1,000), which means that the second trade is what caused you to lose the $500 that you added back (100 x $97 = $9,700 minus the 100 x $102 = $10,200, netting $500 loss). On a net basis, you get to record your loss, it just gets recorded on the second trade. The basis addition lets you work off your wash-sale losses eventually, and in your case, on Day 3 you would recognize a $500 final net loss for tax purposes since you EXITED your position. Caveat: UNLESS you re-enter LMNO within 30 days later (at which point it would be another wash and the basis would shift again). Source: http://www.dummies.com/personal-finance/investing/day-trading/understand-the-irs-wash-sale-rule-when-day-trading/ I can't believe they will tax robots, in Korea, or anywhere else. Yeh, sure, business will agree to that and it surely will help business.  A robot tax is a tax on net income of a business.  If they were serious about Robot tax, then they should have taxed machines first and long time ago. As you know, machines replace more humans than robots do, and machines have much higher productivity than robots.  What's next? Tax computer programs because they automate and replace the work done by humans?   Tax AI because it replaces humans who currently do this analytic work?  Look, it would be silly to tax a machine or robot that does work that no human wants to do or can do.  If the intentions is because Korea wants/need more money from taxes, then tax outsourced work, done by other humans, in countries where labor is cheaper. Or, simply tax the business profits because robots increase their profits.  If the intentions is save jobs done by humans, then regulate robots and, for example, make it a rule that every group of robots must be supervised by humans, or customer service must be done by a human and not a robot/AI. Looks like there are no specific rule in India to prevent Wash sales. See the link below.  http://economictimes.indiatimes.com/wealth/personal-finance-news/investors-can-rejig-portfolio-book-short-term-loss-to-save-tax/articleshow/7812788.cms?intenttarget=no "The difficulty is that you are thinking of a day as a natural unit of time.  For some securities the inventory decisions are less than a minute, for others, it can be months.  You could ask a similar question of ""why would a dealer hold cash?"" They are profit maximizing firms and, subject to a chosen risk level, will accept deals that are sufficiently profitable.  Consider a stock that averages 1,000 shares per day, but for which there is an order for 10,000 shares.  At a sufficient discount, the dealer would be crazy not to carry the order.   You are also assuming all orders are idiosyncratic.  Dividend reinvestment plans (DRIP) trigger planned purchases on a fixed day, usually by averaging them over a period such as 10 days.  The dealer slowly accumulates a position leading up to the date whenever it appears a good discount is available and fills the DRIP orders out of their own account.  The dealer tries to be careful not to disturb the market leading up to the date and allows the volume request to shift prices upward and then fills them." "I don't have anything definitive, but in general positions in a company are not affected materially by what is called a corporate action. ""Corp Actions"" can really be anything that affects the details of a stock. Common examples are a ticker change, or exchange change, IPO (ie a new ticker), doing a split, or merging with another ticker. All of these events do not change the total value of people's positions. If a stock splits, you might have more shares, but they are worth less per share. A merger is quite similar to a split. The old company's stock is converted two the new companies stock at some ratio (ie 10 shares become 1 share) and then converted 1-to-1 to the new symbol. Shorting a stock that splits is no different. You shorted 10 shares, but after the split those are now 100 shares, when you exit the position you have to deliver back 100 ""new"" shares, though dollar-for-dollar they are the same total value. I don't see why a merger would affect your short position. The only difference is you are now shorting a different company, so when you exit the position you'll have to deliver shares of the new company back to the brokerage where you ""borrowed"" the shares you shorted." In the US you specify explicitly what stocks you're selling. Brokers now are required to keep track of cost basis and report it to the IRS on the 1099-B, so you have to tell the broker which position it is that you're closing. Usually, the default is FIFO (i.e.: when you sell, you're assumed to be closing the oldest position), but you can change it if you want. In the US you cannot average costs basis of stocks (you can for mutual funds), so you either do FIFO, LIFO (last position closed first), or specify the specific positions when you submit the sale order.