A generic tag to understand the calculations in a specific case. Please give out a sample illustration and ask a specific question. Ideally should also be accompanied by specific subject tags like "credit-cards", "savings-account", "index-funds" etc.

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7
votes
2answers
558 views

Continuous compounding in practice

A common explanation for the mathematical constant e (2.71828...) is that it is the factor by which an investment would grow at 100% interest rate over a period if it is continuously compounded. In ...
9
votes
7answers
377 views

What single metric is the ultimate measure of personal wealth?

More specifically, what is the single metric you would use to monitor personal wealth?
0
votes
3answers
37 views

Personal Loan issuer online service

I have chunk of money that I would like to loan to my brother. I would like to charge him interest same as banks do. Is there a website or online service where I can enter the "loan" amount, ...
1
vote
3answers
83 views

What is the meaning of “$N industry”?

For example, in the sentence "Semiconductor fabrication is a $100 billion industry.", what exactly is being said?
-1
votes
1answer
40 views

How to calculate forward price for asset with dividend?

I have this exercise question: A particular forward contract costs nothing to enter into at time t and obliges the holder to buy the asset for an amount F at expiry T. The asset pays a dividend DS at ...
4
votes
3answers
91 views

How can I calculate yearly interest of my investment gain?

I'm trying to figure out the yearly interest of a potential investment. Lets say I invested $10 000, 13 days later i cash out and I now have $10 500. The interest here is 4,76% for 13 days. But can I ...
2
votes
2answers
88 views

How to calculate whether it's better to pay my education loan, or my home investment loan?

I have an education loan @ 11.5 % for 1,000,000. I can pay it in 3 years. I am planning to make an investment by buying a home @ 10.5% for 2,200,000. Term = 20 yrs. I am thinking if I sell the house ...
5
votes
3answers
458 views

What is the “rule of 70” or “rule of 72” with regards to investment, and how do I apply it?

What is the "rule of 72" (sometimes called the "rule of 70") with regards to investment, and how do I apply it?
3
votes
3answers
372 views

Negative properties of continuously compounded returns

I'm taking an intro to quant finance course online. I'm trying to better understand the properties and uses of continuously compounded returns. Specifically for this question, how can you have ...
2
votes
2answers
171 views

When to use geometric vs. arithmetic mean? Why is the former better for percentages?

While computing the average price of a stock or index over a period of time, I have the choice between using an arithmetic mean or a geometric mean. Which should I use and when? I am reading a book ...
0
votes
1answer
41 views

Google Finance: Input Parameters For Simple Moving Averages

I'm having some trouble understanding the simple moving average lines that can be added to a quote graph from Google finance. This related Stack Exchange question indicates that the only input ...
2
votes
2answers
102 views

How to calculate ROI on investments? [duplicate]

I looked through the previous questions, and couldn't find one that quite addresses my question. If I start with $1000, and through investing it goes to $1200(100 shares at $10 go to $12), I can say I ...
3
votes
5answers
24k views

How do I calculate net monthly salary (after taxes) in Germany?

If I were to say that my yearly, gross salary was 50,000 euros, then what would be my monthly net after-tax income? For example, this calculator looks OK to me: ...
3
votes
2answers
110 views

How can I calculate (approximate) the future value of my investments? Is this formula appropriate?

I want to check to see if I'm meeting my investment goals, so I want to project forward my assets given a growth rate and a monthly deposit amount. What is the best formula to use for this? Is this ...
2
votes
1answer
58 views

Am I doing the math for this covered call/long put strategy correctly? What risks do I run with this strategy?

In this trade, I write an in-the-money covered call and buy an in-the-money put (as an example) on GM, expiring in September 2014. The call premium is $10.02 with a strike of $26, and the put premium ...
1
vote
1answer
53 views

How can I check if my mortgage balance is correct?

Since I couldn't easily get my unpaid principal balance, I calculated my mortgage balance using a handful of online calculators. Today I took a look at the actual balance, and was rather surprised to ...
1
vote
1answer
44 views

Reasonable alternatives to using the Treasury rate as the risk free rate, e.g. for CAPM calculation?

For all practical purposes, the risk free interest rate is taken to be the short term Treasury bill interest rate. Let's say this rate is 0.5% per annum. But for an individual investor, if his bank ...
5
votes
3answers
703 views

In the event of a corporate spin-off, how can I calculate the correct cost basis for each company's shares?

Consider this example: Siemens is going to have a spin-off (next Monday). If I owned, say, 10,000 shares of Siemens bought at an average price of 80 euros, my cost would be 800,000 euros. In the ...
2
votes
1answer
712 views

How do you calculate the P/E ratio by industry?

I would like to know how to calculate the P/E ratio by industry. On this website, it displays the P/E ratio for the current stock, the industry and the sector: FINANCIALS DTV.O ...
3
votes
1answer
111 views

How to determine withholding so at end of the year I neither owe more, nor get a refund?

A while back I was on a W2 job and I would get a large sum on my tax return. At one point I found a calculator that helped me figure out how to configure my W4 so that I would neither owe nor be owed ...
1
vote
1answer
90 views

How to calculate how far a stock price can drop before a broker would issue a margin call?

Let's say the margin requirement for a stock XYZ is 50%. The current price of XYZ is $150/share. Let us say I put in $100, and borrow $50 from the broker to buy a share. Typically, how far can the ...
2
votes
4answers
1k views

How to calculate money needed for a retirement based on an hypothetical death date & expenses?

I would like to know what formula or tool I need to use to calculate the capital needed for a hypothetical retirement that will start at date X and end at date Y. Here is an example: Variable1 = ...
1
vote
2answers
74 views

Suppose earning an APR of 7% for 5 years, with interest compounded quarterly. What is the EAR? What is the Total Return?

Suppose you earn an APR of 7% for 5 years, with interest compounded quarterly. What is your EAR? What is your Total Return? The part I am confused is "with interest compounded quarterly" The ...
1
vote
2answers
107 views

Calculating accumulated value of an annuity with changing payments?

In a series of 40 payments the first 10 payments are 10 each, the second 10 payments are 20 each, the third 10 payments are 30 each, and the final 10 payments are 40 each. The payments are equally ...
3
votes
2answers
147 views

Need a formula to determine monthly payments received at time t if I'm reinvesting my returns

I need a formula for how much money I will be receiving monthly and how much I will have in total for any time t (in months). The following is my scenario: I will be investing $900 monthly into a 3 ...
2
votes
1answer
93 views

Am I doing the math for this long straddle strategy correctly?

I'm looking at making a long straddle trade, and I'm trying to make sure I have the math correct before making the trade. Here are the details in the example I want to work out: I'm using options on ...
1
vote
1answer
36 views

When performing wash sale calculations does time of day matter?

For wash sales, I've read there is a 30-day window both before and after an opening trade during which a loss from a closing trade becomes a wash sale with respect to the opening trade's cost basis ...
1
vote
0answers
63 views

What are the standard industry practices or disclosures for computing compounded interest on retail deposit accounts in the United States?

I'm seeking to understand how my bank calculates the interest on my various deposit accounts (Money Market, Interest Checking, Savings, Certificate of Deposit) in order to simulate and predict it to a ...
6
votes
5answers
3k views

Why do mortgage affordability recommendations use gross income?

Whenever I see someone ask how to calculate how big a mortgage he can afford, the answer almost always comes back as a percentage of gross income. Why use gross income as the baseline? Why not net ...
3
votes
3answers
140 views

I'm a programmer and need a formula for calculating overal ROI [duplicate]

I'm programming a web app to track my hedge fund performance. I'd like to find my overall ROI for all time. If I had a beginning balance and my current balance then finding the ROI is easy. For ...
0
votes
2answers
202 views

Choosing between two car deals on the same car - NPV

This is basic question, but I have starred myself blind on it - I am stuck. I am not sure which formulae I should use. Here is the story. I am looking to buy a car. I have found two dealerships ...
2
votes
2answers
155 views

How does this retirement fund calculator work?

I found a retirement fund calculator on web: Inflation rate: 2% 0% 2% 0% Expected return rate: 5% 0% 0% ...
3
votes
1answer
121 views

IRS returns more money than my calculation - how can I find out where I was wrong?

A couple of months ago I filed the 2012 tax returns. I was expecting a few thousands USD for a refund. Finally, the payment was received in my bank account, and I noticed that the actual refund was ...
3
votes
4answers
1k views

What's the formula to calculate the monthly or lump-sum investment amount for a desired future value?

Give the following values: Inflation Rate 2% Expected Return Rate 5% Future Value 1,000,000 monetary units Years to Target - 10 What is the formula to calculate the amount of? Lumpsum investment ...
1
vote
2answers
70 views

Why is that we discount all the coupons and par amount of a bond at the same rate?

Why is that we discount all the coupons and par amount of a bond at the same rate, our YTM? If we think of each coupon/par as a strip/single bond on its own, wouldn't then each coupon payment be ...
2
votes
4answers
3k views

Is there a mathematical formula to determine a stock's price at a given time?

I have been trying to find exact information on how stock prices are determined but still I haven't found any exact mathematical formulas how it happens. Wikipedia states: When prospective buyers ...
1
vote
0answers
193 views

Formula to decide when to break a CD?

I'm trying to create a CD comparison tool and have been working on a formula to compare a CD with a higher interest rate to a CD I might own with a penalty period. I believe the basic formula idea: ...
2
votes
2answers
102 views

Calculating the cost of waiting longer for money

I'm trying to calculate the cost of waiting 30 extra days to receive money from a customer. Here's the situation: How much would this cost a company per year if a customer pays us in 60 days vs. ...
9
votes
2answers
303 views

How does compounding of annual interest work?

I have tried reading up on it, but I just find it confusing. Apparently, if you started investing $150/month at a 15% annual return and kept reinvesting the profits, here is what you would have ...
1
vote
2answers
240 views

How to calculate Social Security benefits if retiring before the early Social Security age?

How can I calculate my Social Security if I retire before my early Social Security age? I tried to use the official website's calculator, but it required entering too much data, and the website ...
0
votes
2answers
1k views

How to determine duration of a common stock whose dividends grow in perpetuity?

What is the duration of a common stock whose dividends are expected to grow at a constant rate in perpetuity? Specifically, how can I compute this, since the dividends will grow forever? Update: ...
3
votes
1answer
607 views
1
vote
1answer
88 views

What is the formula for the Tesla Finance calculation?

According to http://www.teslamotors.com/true-cost-of-ownership with the fields set to a rate of 3.3%, down payment 10% over a 72 month term, it calculates this to be $980/mo. How did they get there? ...
3
votes
1answer
730 views

Calculating the profit earned from a leveraged futures contract

How do we calculate the profit/loss of Futures contract? For example, If I had a Futures contract that had $10 000 as the underlying, it had $1000 margin and the Futures contract itself was worth $3. ...
0
votes
2answers
2k views

What is the equation for an inflation adjusted annuity held in perpetuity?

What is the equation relating an initial investment, a fixed rate of return, an inflation rate, and a perpetual payment adjusted for that inflation rate?
2
votes
1answer
87 views

Annuities question - Equations of value

Chuck needs to purchase an item in 10 years. The item costs 200 today, but its price inflates at 4% per year. To finance the purchase, Chuck deposits 20 into an account at the beginning of each ...
6
votes
2answers
296 views

Correct calculation for determining real business book value per share?

I'm trying to calculate the real value of a business and, as an example, I picked Netflix. From their latest financial statements I can see that: Assets value is: $3,065,709,000 Liabilities value ...
2
votes
2answers
99 views

Method for calculating the wisest amount of liability to purchase for car & home insurance?

I've seen the advice to get enough liability insurance as you have in total assets, i.e. if your owned home, owned car & savings = $100,000, then get $100,000 liability coverage. What is the ...
2
votes
1answer
127 views

If I lose 20%, what rate of return do I need to break even?

If the account is down 20%, what rate of return over the next year do we need to get to be even, in other words make back the 20% we lost? The rate of inflation in this case is zero.
1
vote
1answer
100 views

Calculating required rate of return for an income-generating savings account

Say someone has £1m. They want it to generate an increasing level of income, starting from £25k in year 1, and increasing at a rate 7% + inflation pa, such that the end value of the savings after 20 ...