Value of a call option spread
On expiry, with the underlying share price at $46, we have : You ask :  How come they substract 600-100. Why ? Because you have sold the $45 call to open you position, you must now buy it back to close your position.  This will cost you $100, so you are debited for $100 and this debit is being represented as a negative (subtracted); i.e., -$100 Because you have purchased the $40 call to open your position, you must now sell it to close your position.  Upon selling this option you will receive $600, so you are credited with $600 and this credit is represented as a positive (added) ; i.e., +$600. Therefore, upon settlement, closing your position will get you $600-$100 = $500.  This is the first point you are questioning.   (However, you should also note that this is the value of the spread at settlement and it does not include the costs of opening the spread position, which are given as $200, so you net profit is $500-$200 = $300.) You then comment :  I know I am selling 45 Call that means : As a writer: I want stock price to go down or stay at strike. As a buyer: I want stock price to go up. Here, note that for every penny that the underlying share price rises above $45, the money you will pay to buy back your short $45 call option will be offset by the money you will receive by selling the long $40 call option.  Your $40 call option is covering the losses on your short $45 call option. No matter how high the underlying price settles above $45, you will receive the same $500 net credit on settlement.  For example, if the underlying price settles at $50, then you will receive a credit of $1000 for selling your $40 call, but you will incur a debit of $500 against for buying back your short $45 call.  The net being $500 = $1000-$500.  This point is made in response to your comments posted under Dr. Jones answer. I think you're missing the fact that the trader bought the $40 call but wrote the $45 call -- i.e. someone else bought the $45 call from him.  That's why you have to subtract 600-100.  At expiration, the following happens: So $600 + -$100 = $500 total profit. Note: In reality he would probably use the shares he gets from the first call to satisfy the shares he owes on the second call, so the math is even simpler: You have to look at the real price of the share to calculate the value of the spread. 42$ at the start, 46$ at the end.  Think of it this way: When price was 42$ the call 45$ was out of the money, worth 100$ of time value only=100 the call 40$ was in the money and worth 200$ of intrinsic + 100 time value=300 the difference was 200$ Now that price is 46$ the call 45$ is worth 100$ in the money, real or intrinsic value the call 40$ is worth 600$ in the money, real or intrinsic value the difference is 500$ NOTE: 1. Commission fees are not included. 2. Time value of 100$ on both calls when price is 42$ is incorrect and for teaching purpose only. The Explanation is correct. The Traders buys the 1st call and profits linearly form 40$ onwards. At at 45 the short call kick in and neutralizes any further profit on the first call.
Yes. It seems to me you got it right.  On my site, Stock Options Cafe, my last post was an illustration of a bullish call spread. In this case, I bought a 50 call, and sold the 60 call. This is a debit order as I was paying money, not collecting a new premium. "If you make $10 in salary, $5 in interest on savings, and $10 in dividends, your income is $25, not $10. If you have a billion dollars in well-invested assets, you can take a loan against those assets and the interest payment on the loan will be smaller than the interest you earn on the assets. That means your investment will grow faster than your debt and you have a net positive gain. It makes no sense to do this if the value of your asset is static. In that case, you would be better off just to withdraw from the asset and spend it directly, since a loan against that static asset will result in you spending your asset plus interest charges. If you have a good enough rate of return on your investment, you may actually be able to do this in perpetuity, taking out loan after loan, making the loan payments from the loan proceeds, while the value of your original asset pool continues to grow. At any given time, though, a severe downturn in the market could potentially leave you with large debts and insufficient value in your assets to back the debt. If that happens, you won't be getting another loan and the merry-go-round will stop spinning. It's a bit of a Ponzi scheme, in a way. The U.S. government has done exactly this for a long time and has gotten away with it because the dollar has been the world's reserve currency. You could always get a loan against the value of the U.S. currency in the past. Those days may be dwindling, with more countries choosing alternative currencies to conduct business with and the dollar becoming comparatively weaker into the foreseeable future. If you have savings, you can spend more than you make, which will put you into debt, then you can draw down your savings to pay that debt, and at the end of the month you will be out of debt, but have less in savings. You cannot do this forever. Eventually, you run out of savings. If you have no savings, you immediately go into debt and stay there when you spend more than you make. This is simple arithmetic. If you have no savings, but you own assets (real estate, securities, a collection of never-opened Beatles vinyl records, a bicycle), then you could spend more than you make, and be in debt, but have the potential to liquidate assets to pay off all or part of the debt. This depends on finding a buyer and negotiating a price that helps you enough to make a real difference. If you have a car, and you owe $10 on it, but you can only find a buyer willing to pay $8 for the car, that doesn't help you unless you can refinance the $2 and your new payment amount is lower than the old payment amount. But then you're still $2 in debt on the car even though you no longer possess it, and you've still increased your debt by spending more than you made. If you stay on this path, sooner or later you will not have any assets left and you will be in debt, plain and simple. As a wrinkle in the concrete example, let's say you have stock options with your employer. This is a form of a ""call."" You could also purchase a call through a broker in the stock market, or for a commodity in the futures market. That means you pay up front for the right to buy a specific amount of an asset at a fixed price (usually with an expiration date). You don't own the stock, you just have the right to buy it at the call price, regardless of the current market value when you buy it. In the case of employee stock options, your upfront cost is in the form of a vesting schedule. You have to remain employed for a set time before a specific number of stocks become eligible for you to purchase at your option price (the stocks ""vest"" on a certain date). Remain employed longer, and more stocks may vest, depending on your contract. If you quit or are terminated before that date, you forfeit your options. If you stick around through your vesting schedule, you pay real money to buy the stock at your option price. It only makes sense to do this if the market value of the stock is higher than your option price. If the current market value is lower than your option price, you're better off just buying the asset at the current market value, or waiting and  hoping that the value increases before your contract expires. You could drive yourself into debt by spending more than you make, but still have a chance to eliminate your debt by exercising your call/option and then re-selling the asset if it is worth more than what you pay for it. But you may have to wait for a vesting period to elapse before you can exercise your option (depending on the nature of your contract). During this waiting period, you are in debt, and if you can't service your debt (i.e. make payments acceptable to your creditors) your things could get repossessed. Oh, don't forget that you'll also pay a brokerage fee to sell the asset after you exercise your option. Further, if you have exhausted your savings and nobody will give you a loan to exercise your stock (or futures) options, then in the end you would be even further in debt because you already paid for the call, but you are unable to capitalize it and you'll lose what you already paid. If you can get a loan to exercise your option, but you're a bad credit risk, chances are good that the lender will draft a contract requiring you to immediately pay back the loan proceeds plus a fee out of the proceeds of re-selling the stock or other asset. In fact the lender might even draft a contract assigning ownership of your options to them, and stipulating that they'll pay you what's left after they subtract their fee. Even if you can get a traditional loan, you will pay interest over time. The end result is that your debt has still cost you very real money beyond the face value of the debt. Finally, if the asset for which you have a call has decreased in value lower than the current market value, you would be better off buying it directly in the market instead of exercising your option. But you'll pay transaction fees to do that, and the entire action would be pure speculation (or ""investment""), but not an immediate means to pay off your debt. Unless you have reliable insider trading information. But then you risk running afoul of the law. Frankly it might be better to get a loan to pay off your debt than to buy an ""investment"" hoping the value will increase, unless you could guarantee that the return on your investment would be bigger than the cumulative interest and late fees on your debt (or the risk of repossession of your belongings). Remember that nothing you owe a debt on is actually yours, not your house, not your car, not your bicycle, not your smartphone. Most of the time, your best course of action is to make minimum payments on your lowest-interest debts and make extra payments on your highest interest debt, up to the highest total payment you can tolerate (set something aside in a rainy day fund just in case). As you pay off the highest-interest debt, shift the amount you were paying on that debt to make extra payments on your next highest-interest debt until that one is paid off, and repeat on down the line until you're out of debt, then live within your means so that you don't find yourself working at McDonald's because you don't have a choice when you're in your 80's." I can often get the option at [a] price [between bid and ask] The keyword you use here is quite relevant: often. More realistically, it's going to be sometimes. And that's just how supply and demand should work.  The ask is where you know you can buy right away. If you don't wanna buy at ask, you can try and put a higer bid but you can only hope someone will take it before the price moves. If prices are moving up fast, you will have missed a chance if you gambled mid-spread. Having said that, the larger the spread is, the more you should work with limits mid-spread. You don't want to just take ask or bid with illiquid options. Make a calculation of the true value of the option (i.e. using the Black Scholes Model), then set your bid around there. Of course, if not only the option but also the underlying is illiquid, this all gets even more difficult. "First, as @littleadv mentions, and as I've pointed out before, anyone who participates in a market using limit orders (which, by the way, should be every non-professional investor) is by definition a market maker.  So, I will assume that your question pertains both to official market makers and to ""retail investors"" using limit orders. When you remark that there are such ""tight spreads"" in ""liquid assets"", what you are really saying is ""wow, look at all the market makers in these products!""  That's the benefit of electronic trading and algorithmic traders -- millions of participants each with their own opinion of the value of a financial instrument, trying to find people who have very specifically opposing opinions of the value of that same instrument.  This is called price discovery, and is the entire point of financial markets. So, you ask why are there all these market makers present to create such tight spreads in assets like SPY?  Answer: Because they can make money in these markets: Imagine (towards a contradiction) that market makers thought they couldn't make money by offering tight spreads in SPY, and so SPY had a wider spread than it actually does.  For example, say the highest bid for SPY was $99.98 and the lowest ask was $100.01.  Now imagine that a market maker with perfect knowledge of the future came along knowing that he would be able to sell SPY for $100.01 in 5 minutes.  Then he would load up as many buy orders as he could for $100.00 or lower.  (He wouldn't bid $100.01 or higher because those trades would not be profitable according to his information -- at least not 5 minutes from now.)  So the spread had previously been $0.03 and then suddenly it was $0.01, all because a market maker with better information came along and realized he could make money by creating a tighter market! Now, nobody has perfect knowledge of the future, which is why markets are never infinitely tight or infinitely liquid.  Each market maker has to weigh possible profits against the probability that those profits will actually turn into losses.  But if one market maker decides not to participate in a particular instrument, there's bound to be another market maker who will happily take his place.  So the very fact that there are so many market participants with resting buy/sell orders for SPY right now is proof that there are market makers able to make money doing so.  If they could not make money, they wouldn't be there, and the spread would be wider. 10-15 years ago, before electronic trading and algorithmic trading, the number of market participants was far lower, and the spreads were far wider, meaning retail investors like you and me had a much harder time making money.  The only people making money were the institutional investors, the brokers, and the exchanges.  Now that all these new millions of players are present in the market, retail investors like you and me get to participate and make money too." As other uses have pointed out, your example is unusual in that is does not include any time value or volatility value in the quoted premiums, the premiums you quote are only intrinsic values.  For well in-the-money options, the intrinsic value will certainly be the vast majority of the premium, but not the sole component. Having said that, the answer would clearly be that the buyer should buy the $40 call at a premium of $10.  The reason is that the buyer will pay less for the option and therefore risk less money, or buy more options for the same amount of money.  Since the buyer is assuming that the price will rise, the return that will be realised will be the same in gross terms, but higher in relative terms for the buyer of the $40 call.   For example, if the underlying price goes to $60, then the buyer of the $40 call would (potentially) double their money when the premium goes from $10 to $20, while the buyer of the $30 call would realise a (potential) 50% profit when the premium goes from $20 to $30. Considering the situation beyond your scenario, things are more difficult if the bet goes wrong.  If the underlying prices expires at under $40, then the buyer of the $40 call will be better off in gross terms but may be worse off in relative terms (if it expires above $30).  If the underlying price expires between $40 and $50, then the buy of the $30 will be better off in relative term, having lost a smaller percentage of their money. 1.45 and 1.40 are the last trade prices.  The last trade (1.45) for the 27 strike call must have occurred earlier than the last trade (1.40) for the 26 strike call.  These options have low liquidity and don't trade very often.  You have to look at the bid and ask prices to see what people are currently bidding and asking for those options.  As you can see, the premium based on the bids and asks does decrease the further you go out of the money. "You'd need to know the delta and the theta of the option. You can either calculate them yourself using a model like Black-Scholes (assuming you have a market price and can imply a volatility, and know the other factors that go into the model) or, you can see if your broker quotes ""greeks"" as well (mine does). The delta is the sensitivity (rate of change in value) to the underlying stock price, and the theta is the sensitivity to time passing (usually expressed in $/day).  So if your option has a delta of .5 and a theta of -.04, when one day passes and the underlying stock goes up $3, the option will gain roughly $1.50 due to the underlying stock price and lose $0.04 due to time passing." What you want is the distribution yield, which is 2.65. You can see the yield on FT as well, which is listed as 2.64. The difference between the 2 values is likely to be due to different dates of updates. http://funds.ft.com/uk/Tearsheet/Summary?s=CORP:LSE:USD