Trading US stocks from India
I believe I have to pay taxes in US since it is a US broker. No, not at all. The fact that the broker is a US broker has nothing to do with your tax liabilities. You should update the banks and the broker with your change of status submitting form W8-BEN to them. Consult a tax professional proficient with Indo-US tax treaty as to what you should put in part II. The broker might withhold some of your income and remit it as taxes to the IRS based on what you put in W8-BEN and the type of income, but you can have it refunded (if it exceeds your liability) by submitting a tax return (form 1040-NR). You do have to pay tax in India, based on the Indian tax law, for your profits in the US. Consult with an Indian tax accountant on that. If I'm not mistaken, there are also currency transfer restrictions in India that you should be aware of. You can easily go to somebody like icici  ask for the demat section and enable overseas stock trading.
When a delisting happens, the primary process involves, the firm or the entity, trying to buy everyone out so that they can take the firm private by delisting from the stock exchanges. As the firm wants to buy everyone out, the current owners of the equity have the upper hand. They wouldn't want to sell if they believe the firm has a brighter future. So to compensate the existing holders, the buyer needs to compensate the current holders of any future loss, so they pay a premium to buy them out. Hence the prices offered will be more than the current existing price. And in anticipation of a premium the stocks price rises on this speculation. The other scenario is if the current holder(s) decide no to sell their holdings and are small in number, dependent on exchange regulations, and the buyer manages to de-list the stock, the holders might loose out i.e. they have to find another buyer who wants to buy which becomes difficult as the liquidity for the stock is very minimal. if any stock is DE-listed and then we can not trade on it,  In India if the promoters capital is more than 90%, he can get the stock de-listed. There is a process, he has to make an open offer at specified price to minority shareholders. The minority shareholder can refuse to sell. Once the stock is de-listed, it means it cannot be traded on a given exchange. However you can still sell / buy by directly finding a buyer / seller and it's difficult compared to a listed stock. "A non-trading stock or non-marketable security or unlisted security is one that does not trade continually on an exchange. For tax purposes, this can mean a whole new ball of wax which I would prefer the experts address with an edit to this answer or a new answer. For financial accounting purposes, this is when, say, one owns shares in an unlisted corporation and should be treated very carefully less one delude oneself. For trading stock, the value can be known immediately by checking any valid data provider's price and marking to market.  For non-trading stock, the value has to be ""marked to model"".  This can get one into Enron sized trouble. In this case, it's best to either leave the value of the stock at the purchase price and recognize gains upon sale, use a price from another honest transaction by third parties which are most likely difficult to attain, or to use some shorthand measure like applying the market P/E. Be wary of strangely high figures for value from the purchase price by using a market average, and don't throw away the shares just yet if a strangely low one arises.  This method can lead to strange results." Yes, it makes sense. Like Lagerbaer says, the usefulness of technical indicators can not be answered with a simple yes or no. Some people gain something from it, others do not. Aside from this, applying technical indicators (or any other form of technical analysis - like order flow) to instruments which are composed of other instruments, such as indexes (more accurately, a derivative of it), does make sense. There are many theories why this is the case, but personally i believe it is a mixture of self fulfilling prophecy, that the instruments the index is composed of (like the stocks in the S&P500) are traded in similar ways as the index (or rather a trade-able derivative of it like ETFs and futures), and the idea that TA just represents human emotion and interaction in trading. This is a very subjective topic, so take this with a grain of salt, but in contrast to JoeTaxpayer i believe that yields are not necessary in order to use TA successfully. As long as the given instrument is liquid enough, TA can be applied and used to gain an edge. On the other hand, to answer your second question, not all stocks in an index correlate all the time, and not all of them will move in sync with the index. The main difference is that VOO trades on US stock exchanges while VUSA/VUSD trade on the London Stock Exchange.  (VUSA is listed in British pounds while VUSD is listed in US dollars.) They are essentially the same product, but the fees and legal hurdles for a European citizen to trade on the LSE may be quite different from those on US stock exchanges. my tax liabilities in India on my stock profit in US  You would need to pay tax on the profit in India as well after you have become resident Indian. India and US have a double tax avoidance treaty. Hence if you have already paid tax in US, you can claim benefit and pay balance if any. For example if you US tax liability is 20 USD and Indian liability is USD 30, you just need to pay 10 USD. If the Indian tax liability is USD 20 or less you don't need to pay anything.  what if in future I transfer all my US money to India?  The funds you have earned in US while you were Non-Resident is tax free in India. You can bring it back any-time within a period of 7 years. I used to be a trader at a desk that sold delta-one derivatives on listed indices (think swaps, ETFs). There is a LOT to do:   buy/ sell stocks according to redemptions or new orders; manage the currency exposure; indices rebalance their composition everyday based on stock corporate actions, dividends and index reviews - you need to be aware of each and everyone and rebalance your portfolio to account for it; manage your inventory to get the best repo rates possible; trade single stock swaps with foreign counterparties to get access to better tax rates on dividends; when you have a big order where certain stock orders may not get filled - you have to create a strategy for managing that risk; sometimes you hedge your positions using futures that expire every three months in which case you need to figure out the best times to roll your expiring futures; i could go on and on.  Basically, since the profit margins are so low, the market so competitive for such vanilla products, and the volumes so high, you have to really make your processes super efficient and error-proof. Trust me, there is a lot to be done! What typically happens to brokerage accounts during similar situations? This depends on country, time and situation. Nothing is predictable in such situations. In Greece during the said period the stock exchanges were closed for 5 weeks. There was no trading.  Edits: Every situation is different and it would be unfair to compare one against another or use it to predict something else. Right now in India due to demonitization, cash withdrawal is limited. One can trade in stocks, unlimited bank transfers, transfer money out of India ...etc. Everything same except for cash withdrawal. In 1990, the ASEAN countries survived a financial collapse, everything was allowed except moving money out of country. I trade futures. No FX or equities though. It is my only source of income, and has been for about 5 years now.   Equities and FX, to me, seems like more of a gamble than Vegas. I don't know how people do it.