What happens to options after a stock split?
It will be similar to what you have said -- the options price will adjust accordingly following a stock split - Here's a good reference on different scenarios - Splits, Mergers, Spinoffs & Bankruptcies also if you have time to read Characteristics & Risks of Standardized Options Since you asked about Apple, and I happen to have two positions -   This is what happened. I was long the $500, short the $600, in effect, betting Apple would recover from its drop from $700 down to $450 or so. Friday, my target was to hope that Apple remain above $600, but not really caring how much it went over. Now, post split, the magic number is $85.71. My account shows the adjusted option pricing, but doesn't yet show AAPL's new price.
Stock splits are typically done to increase the liquidity of stock merely by converting every stock of the company into multiple stocks of lower face value. For example, if the initial face value of the stock was $10 and the stock got split 10:1, the new face value of the stock would be $1 each. This has a proportional effect on the market value of the stock also. If the stock was trading at $50, after the split the stock should ideally adjust to $5. This is to ensure that despite the stock split, the market capitalization of the company should remain the same. Number of Shares * Stock Price = Market Capitalization = CONSTANT "This answer assumes (based partly on your commants and some simplifying assumptions) As I see it you have a few options. Get a mortgage to buy your sister out. This avoids any ongoing involvement of your sister which may or may not be a good thing. It means you will be paying interest to a bank (or similar financial institution). Make an arrangement to buy the house in installments, possiblly in combination with some kind of rent. Likely to be a complex option to set up. Buy the house using a loan from your sister. potentially agree a ""private mortgage"" to protect your sister in the event you fail to pay. If interest is paid then it is likely to attract tax. Simply pay your sister rent, let her keep ownership of her half of the house either forever or until you have saved up the cash to buy her out. Rent is likely to attract tax. Whatever option you go with I would reccomend you get proffesional advice on any local legal/tax issues and drawing up the contracts. If you do go into an arrangement that keeps your sister involved make sure you discuss the what-ifs upfront and build them into your agreement. If you can't/won't pay what happens? can she insist that the house is sold and the proceeds split in some way? can she rent our her half of the house to someone else?" You can argue that cash dividend is a kind of split as well by this logic. The stock price on ex-dividend gets a hit coincidental with the dividend to be paid, so one can argue that the investor has the same cash value on the day the dividend was paid as if it wouldn't be paid at all. However, for the company to distribute stocks instead of cash may be advantageous if they have low cash reserves but significant amount of treasury stocks, and the stocks are of high liquidity.  It is also a way for the company to release treasury stocks without diluting the current shareholders and creating taxable income to the company, that's an important factor to consider. This is in fact the real answer to your question. The main difference between split and stock dividend is that in split, the stock distributions proportions don't change. With stock dividend - they do. While the outstanding share proportions do not change, total proportions do, because of the treasury stocks being distributed. So company has less stocks in its vaults, but everyone else still has the same proportions of ownership. Compare this to split: company's treasury stocks would be split as well, and it would continue essentially sitting on the same proportion of stocks. That shift of treasury stocks to the outside shareholders - this is what makes it a dividend. "I write software myself and was involved in a couple of start ups.  One failed, another was wildly successful, but I did not receive much in compensation. The former I received stock, but since it failed, it was worthless anyway.  There should be compensation for your time in addition to equity in a company.   Any agreement needs be in writing.  In the later situation I was told to expect about a 17%/year bonus, but nothing could be guaranteed.  Translation:  ""It will never happen.""  It didn't, but I meet my lovely wife there so I have that for a bonus. Agreements need to address the bad things can happen.  What happens if one of you is no longer interested in continuing?  What happens if one of you die, or addicted to something?  What happens if one of you gets thrown in jail or disabled?  Right now you are full of optimism and hope, but bad things happen.  Cover those things while you still like each other. It might be enough to have a good salary, and some stock options.  You man not be interested in running the day to day business. Most of all good luck, I wish you all the best!" It was actually a reverse split meaning that every 10 shares you had became 1 share and the price should be 10x higher. - Citigroup in reverse split The chart just accounts for the split. The big dip is Googles way of showing from what price it split from. If you remember before the split the stock was trading around $4-$5 after the reverse split the stock became 10x higher. Just to clear it up a 1:2(1 for 2) split would mean you get 1 share for every 2 shares you have. This is known as a reverse split.  A 2:1(2 for 1) split means you get 2 shares for every 1 share you have. The first number represents the amount of shares you will receive and the second number represents how many shares you will be giving up. I've never seen a dividend, split or other corporate action during the day, but I have seen trade suspended a few times when something big happened. The market opening price is not in general the same as the close of the previous day. It can gap up or down and does frequently. I don't know of an api to find out if the dividend was cash or stock, but stock dividends are a lot less common. The answer provide by @mbhunter is correct, however there are contexts, shorting in spot market and carrying the position over settlement usually does not entail payment of dividend to the broker, one of the reason being post ex-date the price of the share downward adjusts to the extent of the dividend, so practically if you have shorted at 100 and post ex-date (assuming a dividend of 2 and no movement of the stock price), the price would slide to 98, the party who longed the stock @ 100 now is sitting on a price of 98 and received a dividend of 2 which equates to 100. The above is also contextual to the law of the country governing the exchange and the security exchange board regulations. according to the Options Industry council ( http://www.optionseducation.org/tools/faq/splits_mergers_spinoffs_bankruptcies.html ) put options  the shares (and therefore the options) may continue trading OTC but if the shares completely stop trading then: if the courts cancel the shares, whereby common shareholders receive nothing, calls will become worthless and an investor who exercises a put would receive 100 times the strike price and deliver nothing. The reason for this is that it is not the company whose shares you have the option on that you have a contract with but the counterparty who wrote the option. If the counterparty goes bankrupt then you may not get paid out (depending on assets available at liquidation - this is counterparty risk) but, unless the two are the same, if the company whose shares you have a put option on declares bankruptcy then you will get paid