483. Can the Delta be used to calculate the option premium given a certain target?
One thing I would like to clear up here is that Black Scholes is just a model that makes some assumptions about the dynamics of the underlying + a few other things and with some rather complicated math, out pops the Black Scholes formula. Black Scholes gives you the "real" price under the assumptions of the model. Your definition of what a "real" price entails will depend on what assumptions you make. With that being said, Black Scholes is popular for pricing European options because of the simplicity and speed of using an analytic formula as opposed to having a more complex model that can only be evaluated using a numerical method, as DumbCoder mentioned (should note that, for many other types of derivative contracts, e.g. American or Bermudan style exercise, the Black Scholes analytic formula is not appropriate). The other important thing to note here is that the market does not necessarily need to agree with the assumptions made in the Black Scholes model (and they most certainly do not) to use it. If you look at implied vols for a set of options which have the same expiration but differing strike prices, you may find that the implied vols for each contract differ and this information is telling you to what degree the traders in the market for those contracts disagree with the lognormal distribution assumption made by Black Scholes. Implied vol is generally the thing to look at when determining cheapness/expensiveness of an option contract. With all that being said, what I'm assuming you are interested in is either called a "delta-gamma approximation" or more generally "Greek/sensitivities based profit and loss attribution" (in case you wanted to Google some more about it). Here is an example that is relevant to your question. Let's say we had the following European call contract: Popping this in to BS formula gives you a premium of $4.01, delta of 0.3891 and gamma of 0.0217. Let's say you bought it, and the price of the stock immediately moves to 55 and nothing else changes, re-evaluating with the BS formula gives ~6.23. Whereas using a delta-gamma approximation gives: The actual math doesn't work out exactly and that is due to the fact that there are higher order Greeks than gamma but as you can see here clearly they do not have much of an impact considering a 10% move in the underlying is almost entirely explained by delta and gamma.

484. How do I find the mappings between sedol and isin codes?
You can get this information through Bloomberg, but it's a paid service.

485. Friend was brainwashed by MLM-/ponzi investment scam. What can I do?
As others have stated, it will be very difficult for you to turn your friend around. He has already demonstrated great commitment. What can I do? There may be other people (perhaps mutual friends of you and this man) who are in danger. He may try to get them into this (as he apparently tried to with you). If this was me, I would try to warn the mutual friends of me and him. It's easier to get to them before they have been exposed to the brainwashing. So I would: Yes, I realize this means you're going behind his back, talking to his friends, etc. But I believe these people also deserve to be warned. They are in danger of being adversely affected by what he is doing.

486. Is it better to buy put options or buy an inverse leveraged ETF?
Depends on how far down the market is heading, how certain you are that it is going that way, when you think it will fall, and how risk-averse you are.  By "better" I will assume you are trying to make the most money with this information that you can given your available capital. If you are very certain, the way that makes the most money for the least investment from the options you provided is a put.  If you can borrow some money to buy even more puts, you will make even more.  Use your knowledge of how far and when the market will fall to determine which put is optimal at today's prices.  But remember that if the market stays flat or goes up you lose everything you put in and may owe extra to your creditor.  A short position in a futures contract is also an easy way to get extreme leverage.  The extremity of the leverage will depend on how much margin is required.  Futures trade in large denominations, so think about how much you are able to put to risk. The inverse ETFs are less risky and offer less reward than the derivative contracts above.  The levered one has twice the risk and something like twice the reward.  You can buy those without a margin account in a regular cash brokerage, so they are easier in that respect and the transactions cost will likely be lower. Directly short selling an ETF or stock is another option that is reasonably accessible and only moderately risky.  On par with the inverse ETFs.

487. Should I buy out my brother on a property we will inherit before making improvements?
If your father is still able to make financial decisions and sign contracts, I see a better option. Have your father borrow against his equity to finance the renovation.  Example: the house is worth 400 now. He can borrow 100 against that. He spends it on the addition, making the house worth 500, with the same 400 of equity as before. (In some cases, spending 100 might add 150 to the house value, but let's assume here the increase is just what was spent.) When he dies, the mortgage has to be repaid. If he has no other money (that the two of you would otherwise split) then the mortgage has to be repaid by the two of you putting in cash. So you pay your brother 250 (half the new total value of the house) but he gives 50 of that to the bank for the mortgage. You also give 50 of your own money to the bank for the mortgage. Net result: your brother has 200 (the same as if he had inherited half the unimproved house), and you have a 500 house after paying out 300. Your gain is also the same as if the house was unimproved. Now if the house went up 150 by spending 100, or went up 60 by spending 100, you and your brother would also be sharing this profit or loss. If you don't want that to happen, you will need a different agreement. The advantage of the approach I'm suggesting is you just need one appraisal after your father dies.  Not accounted for in this is that you lived (without paying rent) in your father's house for some time, and that you worked (without being paid) as a caregiver to your father for that time. Some families might think those two things balanced, others might feel you need to be compensated for caring for him, and others that you need to compensate the others for your benefit of living in the large house. Be sure to discuss this with your brother so that you agree in advance whether a plan is fair or not.

488. Is there a free, online stock screener for UK stocks?
I use and recommend barchart.com. Again you have to register but it's free. Although it's a US system it has a full listing of UK stocks and ETFs under International > London. The big advantage of barchart.com is that you can do advanced technical screening with Stochastics and RS, new highs and lows, moving averages etc. You're not stuck with just fundamentals, which in my opinion belong to a previous era. Even if you don't share that opinion you'd still find barchart.com useful for UK stocks.

489. A calculator that takes into account portfolio rebalancing?
My answer is Microsoft Excel.  Google "VBA for dummies" (seriously) and find out if your brokerage offers an 'API'.  With a brief understanding of coding you can get a spreadsheet that is live connected to your brokers data stream.  Say you have a spreadsheet with the 1990 value of each in the first two columns (cells a1 and b1).  Maybe this formula could be the third column, it'll tell you how much to buy or sell to rebalance them.   then to iterate the rebalance, set both a2 and b2 to =C1 and drag the formula through row 25, one row for each year.  It'll probably be a little more work than that, but you get the idea.

490. What are “preferred” stocks? How are they different from normal (common) stocks?
I seem not to be able to comment on the first answer due to reputation, so I'll aim to enhanced the first answer which is generally good but with these caveats: 1) Dividends are not "guaranteed" to preferred shareholders.  Rather, preferred shareholders are normally in line ahead (i.e. in preference to or "preferred") of common shareholders in terms of dividend payment.  This is an extremely important distinction, because unlike investments that we generally consider "guaranteed" such as CDs (known as GICs in Canada), a company's board can suspend the dividend at anytime for long periods of time without significant repercussions -- whereas a missed payment to a bank or secured bondholder can often push a company into bankruptcy very quickly. 2) Due to point 1), it is extremely important to know the "convenants" or rules sorrounding both the preferred shares you are buying and the other more senior creditors of that issuing company (i.e. taxes (almost always come first), banks loans, leases, bonds etc.).  It is also important to know if a particular preferred share has "cumulative" dividends.  You generally only want to buy preferred's that have "cumulative" dividends, since that means that anytime the company misses a payment, they must pay those dividends first before any other dividends at the same or lower priority in the future. 3) Unlike a common stock, your upside on a preferred stock is relatively fixed: you get a fixed share of the company's profit and that's it, whereas a common shareholder gets everything that's left over after interest and preferred dividends are paid. So if the company does really well you will theoretically do much better with common stock over time. For the above reasons, it is generally advisable to think of preferred shares as being more similar to really risky bonds in the same company, rather than similar to common stock.   Of course, if you are an advanced investor there are a lot more variables in play such as tax considerations and whether the preferred have special options attached to them such conversion into common shares.

491. 1040 or 1040NR this time?
Since you were a nonresident alien student on F-1 visa then you will be considered engaged in a trade or business in the USA. You must file Form 1040NR.  Here is the detailed instruction by IRS - http://www.irs.gov/Individuals/International-Taxpayers/Taxation-of-Nonresident-Aliens

492. Is there a “reverse wash sale” rule?
Yes, the newly bought shares will have a long-term holding period, regardless of when you sell them.  In addition, it's only a wash sale if you sold the first shares for a loss; it's not a wash sale if you sold them for a gain. Wikipedia mentions this: When a wash sale occurs, the holding period for the replacement stock includes the period you held the stock you sold. Example: You've held shares of XYZ for 10 years. You sell it at a loss but then buy it back within the wash sale period. When you sell the replacement stock, your gain or loss will be long-term — no matter how soon you sell it. Charles Schwab also mentions this: Here's a quick example of a wash sale. On 9/30/XX, you buy 500 shares of ABC at $10 per share. One year later the stock price starts to drop, and you sell all your shares at $9 per share on 10/4/XY. Two days later, on 10/6, ABC bottoms out at $8 and you buy 500 shares again. This series of trades triggers a wash sale. The holding period of the original shares will be added to the holding period of the replacement shares, effectively leaving you with a long-term position.

493. Would I qualify for a USDA loan?
You probably won't get a mortgage. UDSA has a 41% ratio of monthly debt to monthly income limit, and a score of 660 or better. A 250,000 mortgage at current rates for 30 year mortgage is about $1560/mo. (included in this figure is the 1% mortgage insurance premium, the .4% annual fee, the current rate for a 660 credit rating, the 2% points fee added at the front of the mortgage, typical closing cost added to transaction, and the .5% fee for over-mortgage insurance for the first 3 years since your mortgage will be higher than the value of the house due to these additional fees) Credit card payments = $120 ($60 times 2) Car payments = $542 ($271 for your car, $271 for the car you will be getting) Student loan = $50/month Child Support = $500/month Total = $2772/month Your income per month is 82000/12 = $6833/month $2772/$6833 = 40.6%...  This is awfully close to the limit, so they likely would also look at your ability to save.  Not seeing savings in the above example, I assume it is low.  USDA site One mortgage help site breaks down some of the requirements into layman's language. Not knowing your exact location (county/state) and how many children you have, it is hard to be sure whether you make too much to qualify.  This link shows the income limits by number of people in the house and the county/state.  There are few places in which you could be living that would qualify you to any of their programs unless you have a several children. As others have posted, I suggest you get your debt down.

494. Am I responsible for an annual fee on a credit card I never picked up?
In the end, I was not required to pay the fee. After some frustrating initial attempts, I ended up writing a letter and sending a copy to card services, customer support, complaints and the legal department. It basically said: 1 - I never signed anything. 2 - I spoke to a very aggressive person at the airport who told me that she was just taking down my information in order to send information about the card, and that I was under no obligation 3 - I never received a card, activated a card, or used a card. 4 - I want this charge canceled immediately  5 - If this ever shows up on my credit report, I will contact my lawyer regarding this unscrupulous business practice. After that I received a notice in the mail confirming that everything had been cancelled and all charges were reversed.

495. What expenses do most people not prepare for that turn into “emergencies” but are not covered by an Emergency Fund?
Here's a few. Is this what you're looking for? Also this should probably be a community wiki.

496. What's the difference when asked for “debit or credit” by a store when using credit and debit cards?
Just to add about using debit card as "credit" vs "debit" way: In addition to the difference of having to enter the PIN when using "debit" mode (vs having to sign in "credit" mode), for stores that offer cash back (i.e. get cash out of your account at the same time as paying), you can only get cash back when using "debit" mode.

497. If you buy something and sell it later on the same day, how do you calculate 'investment'?
Nothing wrong with the other answers, but here's a "trick" to hopefully make it totally transparent.   Imagine that you're not the one implementing this business plan, but someone else is.  Let's call this other person your asset manager.  So on the first day, you give your asset manager $9.  He takes this and generates $1 profit from it, recovering the $9 which he then reinvests to generate $1 profit every day.  From your perspective, you just gave him $9.  At the end of the year, he gives you $365 in addition to your original investment of $9 (in real life he'd take the fees of course, or perhaps he's been lending out the money he's been accumulating and taking the interest from that as pay for his services).  So your return on investment is 365 / 9 * 100 % > 4000 %, as claimed by your source.

498. Should I stockpile nickels?
The collectible value of coins will probably increase with the underlying metal value. I'd collect coins for that reason and because I enjoy collecting them. I wouldn't recommend buying bags of rolled nickels or anything though.

499. Is a stock's trade size history publicly available?
My Broker and probably many Brokers provide this information in a table format under "Course of Sale". It provides the time, price and volume of each trade on that day. You could also view this data on a chart in some charting programs. Just set the interval to "Tick by Tick" and look at the volume. "Tick by Tick" will basically place a mark for every trade that is taken and then the volume will tell you the size of that trade.
