Clarification on options jargon regarding spreads
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 sold bought a call option then as you stated sold it to someone else what you are doing is selling the call you bought. That leaves you with no position.  This is the case if you are talking about the same strike, same expiration. "Figured it out.  Vertical spreads significantly reduce the amount of ""buying power"" on the account needed vs. buying / selling pure calls / puts.  So even though the transaction fees may more double in some instances, it may be worth it in order to operate with pricier underlying instruments. Spreads are also considered ""defined risk"" trades where both the profit and loss are capped per how the spreads are setup.  This is compared to single calls / puts where either the upside or the downside can be unlimited.  So for times when the expected move is not as pronounced, a spread may be a better fit depending on environment and other factors." This sometimes happens to me. It depends on how liquid the option is. Normally what I see happening is that the order book mutates itself around my order. I interpret this to mean that the order book is primarily market makers. They see a retail investor (me) come in and, since they don't have any interest in this illiquid option, they back off. Some other retail investor (or whatever) steps in with a market order, and we get matched up. I get a fill because I become the market maker for a brief while. On highly liquid options, buy limits at the bid tend to get swallowed because the market makers are working the spread. With very small orders (a contract or two) on very liquid options, I've had luck getting quick fills in the middle of the spread, which I attribute to MM's rebalancing their holdings on the cheap, although sometimes I like to think there's some other anal-retentive like me out there that hates to see such a lopsided book. :) I haven't noticed any particular tendency for this to happen more with puts or calls, or with buy vs sell transactions. For a while I had a suspicion that this was happening with strikes where IV didn't match IV of other strikes, but I never cared enough to chase it down as it was a minor part of my overall P/L. Basic arbitrage is the (near-)simultaneous purchasing and selling of things that are convertible.   The classic example is the international trading of equities. If someone in London wants to purchase a hundred shares of Shell for 40 GBP ea. and someone in New York wants to sell you a hundred shares of Shell for 61 USD ea., you can buy the shares from the guy in New York, sell them to the guy in London and convert your GBP back in to USD for a profit of $41.60 minus fees.  Now, if after you buy the shares in New York, the price in London goes down, you'll be left holding 100 shares of Shell that you don't want. So instead you should borrow 100 shares in London and sell them at the exact same time that you buy the shares in New York, thus keeping your net position at 0. In fact, you should also borrow 4000GBP and convert them to USD at the same time, so that exchange rate changes don't get you. Depending on the structure of you're portfolio, it could be that your portfolio is delta neutral to take advantage of diminishing time value on options, short straddles/strangles would be an example. Just adding on a touch, when market participants refer to swaps they are talking about the fixed leg.   So for example, if I said a 5y Receiver, it means I am receiving fixed, paying floating. Ie I want yields to fall. Opposite for a Payer.  Swaption is just an option on these swaps, so basic swaptions:  Long Payer Short Payer Long Receiver Short Receiver 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. "Is there ever any ambiguity on what that that exact strike is in delta space, or does everyone back it out from the pricing model the same way?  I ask, because in my product nearly everyone runs a heavier delta to the put (the severity of that varies). So on trades that are ""tied up"", everyone participating on it can have slightly different deltas that they are modeling" a smaller spread indicates a flat yield curve, which means banks and investors are uncertain about future economic conditions (like the current environment).   When the spread widens and the curve becomes upward sloping (considered a normal yield curve), investors expect future growth and minimal inflation. Longer term rates increase as investors demand a higher yield in return for lending their money for a longer period of time. Increase demand for credit (industries expanding) also drive up longer term rates.   A negative spread indicates an inverted yield curve and investors believe the economy is overheating and interest rates will fall. Investors pull money out of the stock market and into long term bonds (raising the price, lowering the yield) while companies stop borrowing, reducing the demand for credit and lower the cost, or interest rate, on a loan.   Keep in mind central banks determine short term rates, so inverted curves are rare in the sense the market perceives uncertainty and rushes to safety (bonds) before the central bank reacts and lowers short term rates. It's a covered call.  When I want to create a covered call position, I don't need to wait before the stock transaction settles. I enter it as one trade, and they settle at different times. "Write means sell to open.  It is called that because options writers are creating (i.e. writing) new contracts. No such thing as ""reading"" an option." "Defining parity as ""parity is the amount by which an option is in the money"", I'd say there may be an arbitrage opportunity. If there's a $50 strike on a stock valued at $60 that I can buy for less than $10, there's an opportunity.  Keep in mind, options often show high spreads, my example above might show a bid/ask of $9.75/$10.25, in which case the last trade of $9.50 should be ignored in favor of the actual ask price you'd pay.  Mispricing can exist, but in this day and age, is far less likely." G spread - you have a 5.5 year bond, you take your yield minus the yield on the 5.5y point (interpolated) of the benchmark sovereign curve. Think of G = Government.      I Spread - same as G Spread but you use the relevant Swap Curve. E.g. USD bond, compare against the USD Swaps curve. I = interpolated.      Z Spread - stands for zero volatility curve spread. You strip the swaps curve to get zero rates (i.e. Zero coupon rates for each tenor), then find the constant spread on top of each part of the curve's zero rates to arrive at your bond's yield.      In G and I Spread, you're basically discounting the bond's cash flows using one rate (i.e. The interpolated yield on the curve). With Z Spread, you're discounting using the entire portion of the curve that's relevant to your bond's maturity. Being long something is the same as owning it (generally). Being short something is the same as selling it, with the intention (actually obligation) of buying it back in the future. Being 'short' means that you benefit when the price falls.  A call is the right to buy a financial asset, most often a share, at some price agreed upon now, while the the right extends for some defined time into the future. A put is the right to sell something you already own for some price defined now but the right extends for some period into the future.  A swaption is an option to enter into a swap. A swap is an agreement to trade cash-flows at defined points in the future, usually some fixed rate for some floating rate (say LIBOR+200bps).  EDIT: Clarified puts. You'd likely be most familiar with them with respect to options and futures on commodities but they're used for credit/interest as well. The intrinsic value of an option is *derived* from the spread between call/put price and strike price; the value of the contract I've paid for or sold is derived from the current market value of the underlying asset, be it rice, platinum, or the Swedish kroner