ISA - intra year profits and switching process
You're overthinking it. The ISA limit applies to the amount you invest into the ISA. In your example, £10,000. Whether that then fluctuates with performance is irrelevant. Even if you realise aprofit or a loss, nobody is watching it. You merely count the amount you originally contributed into the ISA wrapper. When they add up to £15,000; that's the limit reached. (And by the way, remember that only money going into the ISA is counted. It doesn't matter if you -let's say - put £15k in, then remove 10k. You've reached the limit. You don't again have the chance to put £10k 'back in'. An ISA is a much simpler thing than I suspect you think it is. It is a wrapper or envelope, and the point of it is that HMRC does not care what happens inside the envelope, or even about extractions of funds from the envelope; they only care about insertions of funds into the envelope. It is these insertions that are limited to £15k in a tax year; what happens to the funds once they're inside the envelope is your own business.  Some diagrams: Initial investment of £10k. This is an insertion into the envelope and so counts against your £15k/tax year limit.                 +---------ISA-------+ ----- £10k --------->              |                +-------------------+  So now you have this:                 +---------ISA-------+                |  £10k of cash     |                +-------------------+  Buy fund:                 +---------ISA-------+                |    £10k of ABC    |                +-------------------+  Fund appreciates. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £12k of ABC    |                +-------------------+  Sell fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £12k of cash   |                +-------------------+  Buy another fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-----------------+                | £10k of JKL & £2k of cash   |                +-----------------------------+  Fund appreciates. This happens inside the envelope; HMRC don't care:                 +---------ISA-----------------+                | £11k of JKL & £2k of cash   |                +-----------------------------+  Sell fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £13k of cash   |                +-------------------+  Withdraw funds. This is an extraction from the envelope; HMRC don't care.                 +---------ISA-------+ <---- £13k ---------               |                +-------------------+  No capital gains liability, you don't even have to put this on your tax return (if applicable) - your £10k became £13k inside an ISA envelope, so HMRC don't care. Note however that for the rest of that tax year, the most you can insert into an ISA would now be £5k:                 +---------ISA-------+ ----- £5k --------->               |                +-------------------+  even though the ISA is empty. This is because the limit is to the total inserted during the year.
Your existing shares in their existing ISA(s) do not in any way impact on your future ISA allowances. The only thing that uses up your ISA allowance is you paying new cash into an ISA account. So you can leave your existing shares in their existing ISA(s) and simply open new ISA(s) for future contributions which suit your current plans. Technically, the answer is no, you can't put more money in to that ISA in that tax year once you've transferred it (unless you've transferred it to a Stocks and Shares ISA). FAQs 7 and 8 from http://www.hmrc.gov.uk/isa/faqs.htm cover these cases: Q. I have transferred current year payments to my cash ISA to a stocks   and shares ISA, can I make any further payments to a cash ISA in this   tax year? A. Yes - provided you haven't already used up your annual ISA   investment allowance (£11,520 in the tax year 2013-14). When you transfer current year payments to your cash ISA to a stocks   and shares ISA it is as if that cash ISA had never existed. Any money   you saved up to the date of transfer will be treated as if you had   invested that money directly in the stocks and shares ISA. For example, if you had put £2,000 in a cash ISA and then transferred   it to a stocks and shares ISA you would be able to make further   payments totalling £9,520 in that tax year. You could either put all   of the £9,520 in the stocks and shares ISA or you could put up to   £5,760 in a cash ISA (with the same or a different ISA manager) and   the remainder of the £9,520 in the stocks and shares ISA.  Q. How many ISAs can I have? A. There are limits on the number of ISA accounts you can subscribe to   each tax year. You can only put money into one cash ISA and one stocks   and shares ISA. But in different years, you could choose to save with different   managers. There are no limits on the number of different ISAs you can   hold over time. However, in practice, if you transfer mid-year from Provider A to Provider B, Provider B has no way of telling whether you have already put money in to the ISA with Provider A that year or not, so you will be able to put more money in.  I believe that ISA providers do report their subscriptions back to HMRC so they can check for multiple subscriptions (over the limit) in one tax year; but in the past, I have done exactly what you describe and it has never been picked up in any way or caused any problem at all. As long as you stick to total subscriptions within the limit, I'd guess you're unlikely to encounter a problem. (Of course I am not a financial advisor so you should take what I say with the same pinch of salt as you would take any other random advice from the internet). "I interned for about six months at a firm that employed a few technical analysts, so I'll try to provide what little information I can. Since the bulk of the intra-day trading was decided algorithmically, technical analysts had two main functions: This basically boils down to my answer to your question. There are still enough people, trading firms, etc. who believe in candlestick charting and other visually subjective patterns that if you notice a trend, pattern, etc. before the majority of traders observing, you may be able to time the market successfully and profit. This is becoming increasingly dangerous, however, because of the steps I outlined above. Over time, the charting patterns that have been proven effective (often in many firms individually since the algorithms are all proprietary) are incorporated into computer algorithms, so the ""traders"" you're competing with to see the pattern are increasingly low-latency computer clusters less than a few blocks from the exchange. Summary: Candlestick charting, along with other forms of subjective technical analysis, has its believers, and assuming enough of these believers trade the standard strategies based on the standard patterns, one could conceivably time the market with enough skill to anticipate these traders acting on the pattern and therefore profit. However, the marginal benefits of doing so are decreasing rapidly as computers take over more trading responsibility.  Caveats:  I know you're in Australia, where the market penetration of HF/algo traders isn't as high as in the US, so it might be a few more years before the marginal benefits cease to be profitable; that being said, if various forms of technical analysis proved wildly profitable in Australia, above and beyond profits available in other markets, rest assured that large American or British trading firms would already have moved in.  My experience is limited to one trading firm, so I certainly can't speak for the industry as a whole. I know I didn't address candlestick charts specifically, but since they're only one piece of visual technical analysis, I tried to address the issue as a whole.  This somewhat ties into the debate between fundamental or technical analysis, which I won't get into. Investopedia has a short article on the subject. As I said, I won't get into this because while it's a nice debate for small traders, at large trading firms, they don't care; they want to make profit, and any strategy that can be vetted, whether it's fundamental, technical, or astrological, will be vetted.  I want to add more information to my answer to clear up some of the misconceptions in the comments, including those talking about biased studies and a lack of evidence for or against technical analysis (and candlestick charts; I'll explore this relationship further down).  It's important to keep in mind that charting methods, including candlestick charts, are visually subjective ways of representing data, and that any interpretations drawn from such charts should, ideally, represent objective technical indicators. A charting method is only as good as the indicators it's used to represent. Therefore, an analysis of the underlying indicators provides a suitable analysis for the visual medium in which they're presented.  One important study that evaluates several of these indicators is Foundations of Technical Analysis: Computational Algorithms, Statistical Inference, and Empirical Implementation by Lo, Mamaysky, and Wang. Lest anyone accuse its authors of bias, I should point out that not only is it published by the National Bureau of Economic Research (a highly reputable organization within economics and finance), but also that the majority of its authors come from MIT's Sloan school, which holds a reputation second to none. This study finds that several technical indicators, e.g. head-and-shoulder, double-bottom, and various rectangle techniques, do provide marginal value. They also find that although  human judgment is still superior to most computational algorithms in the area of visual pattern recognition, ... technical analysis can be improved by using automated algorithms Since this paper was published in 2000, computing power and statistical analysis have gained significant ground against human ability to identify and exploit for visual pattern detection like candlestick charts.  Second, I suggest you look into David Aaronson's book, Evidence-Based Technical Analysis: Applying the Scientific Method and Statistical Inference to Trading Signals. He finds similar results to the Lo, et. al. paper, in that some technical indicators do add value to the investment process, but those that do are those that can be represented mathematically and thus programmed directly into trading algorithms (thus bypassing visual tools like candlestick charts).  He describes how studies, including Lo, et al., have found that head and shoulders patterns are worse than random, i.e. you would earn higher returns if you simply traded at random. That point is worth than repeating. If a day-trader is using a candlestick chart and using head-and-shoulders patterns as part of their toolkit, he's rolling the dice when he uses that pattern and returns that come from its application come from chance. This reminds me of that old story about a company that sends out pamphlets predicting the results of sports games, complete with ""strategies"" and ""data"" to back up the predictions. The company sends out several versions of the pamphlet every game, each predicting a different winner. Given a large enough sample size, by the end of the season, there are a few people who have received a pamphlet that accurately predicted the winner for every game and they're convinced the system is perfect. The others weren't so lucky, however. Relying on candlestick charts and TA patterns that are relics from the pre-computerized era is reassuring to some traders and gives them a sense of control and ""beating the market,"" but how long will chance remain on your side? This is why I maintain that visual tools like candlestick charts are a slowly dying medium. They certainly still add value to some trading firms, which is why Bloomberg terminals still ship with this functionality built in, but as more and more research shows, automated algorithms and statistical indicators can provide more value. It's also important to think about whether the majority of the value added by visual tools like candlestick charts comes in the form of profit or a sense of security to traders who learned the field using them over the past few decades.  Finally, it's extremely important to realize that the actions of retail investors in the equities market cannot begin to represent the behaviors of the market as a whole. In the equities markets alone, trading firms and institutional investors dwarf retail investors, and the difference in scale is even more vastly pronounced in derivatives and currency markets. The fact that some retail investors use candlestick charts and the technical indicators they (hope) underlie them provides nothing but minor anecdotal evidence as to their effectiveness." "This question has been asked and answered before. Financially, owning a car will be more economical than leasing one in most cases. The reason for this is that leasing arrangements are designed to make a profit for the leasing company over and above the value of the car. A leasing company that does not profit off their customers will not be in business for long. This is a zero-sum game and the leasing customer is the loser. The lion's share of the customer losses are in maintenance and in the event of an accident or other damage. In both cases, leasing arrangements are designed to make a large profit for the owner. The average customer assumes they will never get into an accident and they underestimate the losses they will take on the maintenance. For example, if both oxygen sensors need to be replaced and it would have cost you $800 to replace them yourself, but the leasing company charges you $1200, then BOOM! you just lost $400. If the car is totaled, the customer will lose many thousands of dollars. Leasing contracts are designed to make money for the owner, not the customer. Another way leasing agents make money is on ""required maintenance"". Most leasing contracts require the leasor to perform ""required"" maintenance, oil changes, tire rotations, etc. Also, with newer cars manufacturers recalls are common. Those are required as well. Nearly nobody does this maintenance correctly. This gives the agent the excuse to charge the customer thousands of dollars when the vehicle is returned. Bills of $4000 to $6000 on a 3 year lease for failure to perform required maintenance are common. Its items like this that allow the leasing agent to get a profit on what looks like a ""good deal"" when the customer walked in the door 3 years previously. The advantage of leasing is that it costs less up front and it is more convenient to switch to a different car because you don't have to sell the car." If you take the profit or loss next year, it counts on next year's taxes.  There's no profit or loss until that happens. This investment strategy may have tax advantages. In some countries, income received from dividends is taxed as income, whereas profits on share trades are capital gains. If you have already exceeded your tax-free income limit for the year, but not your capital gains tax allowance, it may be preferable to make a dealing profit rather than an investment income. These arrangements are called a bed-and-breakfast. Yes, if your IRR is 5% per annum after three years then the total return (I prefer total rather than your use of actual) over those three years is 15.76%. Note that if you have other cashflows in and out, it gets a bit more complicated (e.g. using the XIRR function in Excel), but the idea is to find an effective annual percentage return that you're getting for your money. There's no unique way to split the profit, it's about claims and arguments.  I propose the approach based on internal rate of return. Consider we have a project with cash flow -500 at the beginning, -1000 at 3 months and +2300 (1000 profit - 200 fee + 1500 of initial investments) at 1 year. The balance looks as follows (simple compounding): The solution is r = 64% (not bad!). Now, the value of the 1-st investment is 500*(1+0.64)=820 and the value of the second is 1000*(1+0.64*0.75)=1480 (at t=1 year). This gives the shares of 35.65% (820/2300) and 64.35% (1480/2300). Then split the profit according to the shares.