Buying and selling the same stock
Elaborating on kelsham's answer: You buy 100 shares XYZ at $1, for a total cost of $100 plus commissions. You sell 100 shares XYZ at $2, for a total income of $200 minus commissions. Exclusive of commissions, your capital gain is $100 for this trade, and you will pay taxes on that.  Even if you proceed to buy 200 shares XYZ at $1, reinvesting all your income from the sale, you still owe taxes on that $100 gain.  The IRS has met this trick before. "Unfortunately, we don't know your country, but I'd guess ""Not US"" with the hint being your use of the word bugger in a comment.  Realized profits are taxed by all tax authorities I'm aware of, i.e. the Tax Man in every country. Annually, so that you can let the profits run during the year, and offset by the losses during that year.  The exception is within a qualified retirement account. Many countries offer accounts that will let you do just what you're suggesting, start with XXX number of Quatloos in your account, trade for decades, and only take the tax hit on withdrawal. In some cases there's an opportunity to fund the account post tax, and never pay tax again. But to repeat, this is with a retirement account, not the usual trading accounts." Sorry, no, any time you sell for a profit you owe tax. If you buy for $1 and sell $1 when the price goes to $2, you would have sold only half of your initial investment. So your investment would now be worth $2 and you sell $1 leaving $1 still in the market.  This means you would have sold half your initial investment, making a profit of $0.50 on this half of your initial investment, and having to pay CGT on this amount. I think what you're asking is,  Can I buy 1000 shares of the stock at $1.  For $1000.   it goes up to $2, then sell 500 shares of the stock with proceeds of $1000, now   having my original $1000 out of it, and still owning 500 shares.    And that not create a taxable event. Since all I   did was take my cost basis back out, and didn't collect any gains.   And then I want to repeat that over and over. Nope, not in the USA anyway.   Each sale is a separate taxable event. The first sale will have proceeds of $1000 and a cost basis of $500, with $500 of capital gains, and taxes owed at the time of that sale. The remaining stock will have a cost basis of $500 and proceeds of whatever you sell it for in the future. The next batch of stock will have a cost basis of whatever you pay for it.   The only thing that works anything like the way you're thinking, is a Roth IRA...   You can put your cost basis in, pull it back out, and put it back in again, all tax free.   But every time your cost basis cycles in, that counts towed your contribution limits unless you do it fast enough to call it a rollover. No, you can not cheat the IRS. This question is also based on the assumption that the stock will return to $1 which isn't always a safe assumption and that it will continue to cycle like that repeatedly which is also likely a false assumption.
"Vitalik has mentioned this in a comment but I think it ought to be expanded upon: Companies that aren't already penny stocks really don't stand to gain anything from trying to prevent short interest.  Short selling does not inherently lower the stock price - not any more so than any other kind of selling.  When somebody shorts a stock, it's simply borrowed from another investor's margin; as long as it's not a naked short resulting in an FTD (Failure To Deliver) then it does not add any ""artificial"" selling pressure. In fact, shorting can actually drive the price up in the long term due to stops and margin calls.  Not a guarantee, of course, but if a rally occurs then a high short interest can cause a cascade effect from the short ""squeeze"", resulting in an even bigger rally than what would have occurred with zero short interest.  Many investors actually treat a high short interest as a bullish signal. Compare with margin buying - essentially the opposite of short selling - which has the opposite effect.  If investors buy stocks on margin, then if the value of that stock decreases too rapidly they will be forced to sell, which can cause the exact same cascade effect as a short interest but in the opposite direction.  Shorting is (in a sense) evening out the odds by inflating the buying pressure at lower stock prices when the borrowers decide to cover and take profits. Bottom line is that, aside from (illegal) insider trading, it doesn't do businesses any good to try to manipulate their stock price or any trading activity.  Yes, a company can raise capital by selling additional common shares, but a split really has no effect on the amount of capital they'd be able to raise because it doesn't change the actual market cap, and a dilution is a dilution regardless of the current stock price.  If a company's market cap is $1 billion then it doesn't matter if they issue 1 million shares at $50.00 each or 10 million shares at $5.00 each; either way it nets them $50 million from the sale and causes a 5% dilution, to which the market will react accordingly. They don't do it because there'd be no point." Purchases and sales from the same trade date will both settle on the same settlement date. They don't have to pay for their purchases until later either. Because HFT typically make many offsetting trades -- buying, selling, buying, selling, buying, selling, etc -- when the purchases and sales settle, the amount they pay for their purchases will roughly cancel with the amount they receive for their sales (the difference being their profit or loss). Margin accounts and just having extra cash around can increase their ability to have trades that do not perfectly offset. In practice, the HFT's broker will take a smaller amount of cash (e.g. $1 million) as a deposit of capital, and will then allow the HFT to trade a larger amount of stock value long or short (e.g. $10 million, for 10:1 leverage). That $1 million needs to be enough to cover the net profit/loss when the trades settle, and the broker will monitor this to ensure that deposit will be enough. "Your assertion that you will not be selling anything is at odds with the idea that you will be doing tax loss harvesting.  Tax loss harvesting always involves some selling (you sell stocks that have fallen in price and lock in the capital losses, which gives you a break on your taxes).  If you absolutely prohibit your advisor from selling, then you will not be able to do tax loss harvesting (in that case, why are you using an advisor at all?). Tax loss harvesting has nothing to do with your horizon nor the active/passive difference, really. As a practical matter, a good tax loss harvesting plan involves mechanically selling losers and immediately putting the money in another stock with more-or-less similar risk so your portfolio doesn't change much.  In this way you get a stable portfolio that performs just like a static portfolio but gives you a tax benefit each year.  The IRS officially prohibits this practice via the ""wash sale rule"" that says you can't buy a substantially identical asset within a short period of time.  However, though two stocks have similar risk, they are not generally substantially similar in a legal sense, so the IRS can't really beat you in court and they don't try.  Basically you can't just buy the same stock again. The roboadvisor is advertising that they will perform this service, keeping your portfolio pretty much static in terms of risk, in such a way that your tax benefit is maximized and you don't run afoul of the IRS." Gold is traded on the London stock exchange (LSE) and the New York stock exchange (NYSE) under various separate asset tickers, mainly denominated in sterling and US dollars respectively.  These stocks will reflect FX changes very quickly.  If you sold LSE gold and foreign exchanged your sterling to dollars to buy NYSE gold you would almost certainly lose on the spreads upon selling, FX'ing and re-buying. In short, the same asset doesn't exist in multiple currencies.  It may have the same International Securities Identification Number (ISIN), but it can trade with different Stock Exchange Daily Official List (SEDOL) identifiers, reflecting different currencies and/or exchanges, each carrying a different price at any one time. "Scenario 1 - When you sell the shares in a margin account, you will see your buying power go up, but your ""amount available to withdraw"" stays the same until settlement. Yes, you can reallocate the same day, no need to wait until settlement. There is no margin interest for this scenario.  Scenario 2 -  If that stock is marginable to 50%, and all you have is $10,000 in that stock, you can buy another $10,000. Once done, you are at 50% margin, exactly." Will there be a scenario in which I want to sell, but nobody wants to buy from me and I'm stuck at the brokerage website? Similarly, if nobody wants to sell their stocks, I will not be able to buy at all? You're thinking of this as a normal purchase, but that's not really how US stock markets operate. First, just because there are shares of stock purchased, it doesn't mean that there was real investor buyer and seller demand for that instrument (at that point in time).  Markets have dedicated middlemen called Market Makers (NASDAQ) or Specialists (NYSE), who are responsible to make sure that there is always someone to buy or sell; this ensures that all instruments have sufficient liquidity.  Market Makers and specialists may decide to lower their bid on a stock based on a high number of sellers, or raise their ask for a high number of buyers. During an investor rush to buy or sell an instrument (perhaps in response to a news release), it's possible for the Market Maker / specialist to accumulate or distribute a large number of shares, without end-investors like you or I being involved on both sides of the same transaction. In general stock markets are very similar to that, however, you can also put in limit orders to say that you will only buy or sell at a given price. These sit in the market for a specified length of time and will be executed when an order arrives that matches the price (or better). Traders who set limit orders are called liquidity (or price) makers as they provide liquidity (i.e. volume to be traded) to be filled later. If there is no counterparty (i.e. buyer to your seller) in the market, a market maker; a large bank or brokerage who is licensed and regulated to do so, will fill your order at some price. That price is based on how much volume (i.e. trading) there is in that stock on average. This is called average daily volume (ADV) and is calculated over varying periods of time; we use ADV30 which is the 30 day average. You can always sell stocks for whatever price you like privately but a market order does not allow you to set your price (you are a price taker) therefore that kind of order will always fill at a market price. As mentioned above limit orders will not fill until the price is hit but will stay on book as long as they aren't filled, expired or cancelled. I'm going to assume that you want to be invested all the time and each trade consists in selling a security and buying another one (similar to your example). How much commissions you are willing to pay depends on several factors, but one way to think about it is as follows. You have a position in stock A and you want to switch to stock B because you think it will perform better. If you think there's a good chance (>50%) that B will outperform A by more than x% then you can happily pay up to x/2% commissions and still make money over a long time horizon. If you like formulae, one way to express it is: Where: Example: if you tend to be right 51% of the time (hit rate), and gain 110% more than you lose on average (win loss ratio), you can see that your expected profit is: 5.1% - commissions, so you could pay 2.5% commissions on entering and closing the position and still make money*. Unfortunately, common sense, statistics and numerous studies tell us a sad truth: on average, people have a hit rate of 50% and a win/loss ratio of 100%. Which means that their expected profit per trade is 0% - commission. Based on that crude observation - unless you can prove to yourself that you are better than average - you should aim at reducing commissions paid to your broker as much as possible through: * 51% and 110% are not random numbers, they correspond to the results of the top 15% (professional) managers in a research paper using a sample of 215 funds managing $150bn.