Margin Calculations Question
The setup is a purchase of 200 shares at $40 with a cash deposit of $4000 and margin loan of $4000 which a year later grew to $4240. With a margin requirement of 30%, the loan can be 70% or a total stock value of $6057. 1) $30.29 2) -24.3% (The stock fell to $30.29 from $40) 3) -54.6% (Your $4000 fell to $1817)
"First, the balance sheet is where assets, liabilities, & equity live. Balance Sheet Identity: Assets = Liabilities (+ Equity) The income statement is where income and expenses live. General Income Statement Identity: Income = Revenue - Expenses If you want to model yourself correctly (like a business), change your ""income"" account to ""revenue"". Recognized & Realized If you haven't yet closed the position, your gain/loss is ""recognized"".  If you have closed the position, it's ""realized"". Recognized Capital Gains(Losses) Assuming no change in margin requirements: Margin interest should increase margin liabilities thus decrease equity and can be booked as an expense on the income statement. Margin requirements for shorts should not be booked under liabilities unless if you also book a contra-asset balancing out the equity.  Ask a new question for details on this. Realized Capital Gains(Losses) Balance Sheet Identity Concepts One of the most fundamental things to remember when it comes to the balance sheet identity is that ""equity"" is derived. If your assets increase/decrease while liabilities remain constant, your equity increases/decreases. Double Entry Accounting The most fundamental concept of double entry accounting is that debits always equal credits. Here's the beauty: if things don't add up, make a new debit/credit account to account for the imbalance.  This way, the imbalance is always accounted for and can help you chase it down later, the more specific the account label the better." "An index is just a mathematical calculation based on stock prices. Anyone can create such a calculation and (given a little effort) publish it based on publicly available data. The question of ""open source"" is simply whether or not the calculator chooses to publish the calculation used. Given how easy an index is to create, the issue is not the ""open source"" nature or otherwise, but its credibility and usefulness." I'm not entirely sure about some of the details in your question, since I think you meant to use $10,000 as the value of the futures contract and $3 as the value of the underlying stock. Those numbers would make more sense. That being said, I can give you a simple example of how to calculate the profit and loss from a leveraged futures contract. For the sake of simplicity, I'll use a well-known futures contract: the E-mini S&P500 contract. Each E-mini is worth $50 times the value of the S&P 500 index and has a tick size of 0.25, so the minimum price change is 0.25 * $50 = $12.50.  Here's an example. Say the current value of the S&P500 is 1,600; the value of each contract is therefore $50 * 1,600 = $80,000. You purchase one contract on margin, with an initial margin requirement1 of 5%, or $4,000. If the S&P 500 index rises to 1,610, the value of your futures contract increases to $50 * 1,610 = $80,500. Once you return the 80,000 - 4,000 = $76,000 that you borrowed as leverage, your profit is 80,500 - 76,000 = $4,500.  Since you used $4,000 of your own funds as an initial margin, your profit, excluding commissions is 4,500 - 4,000 = $500, which is a 500/4000 = 12.5% return. If the index dropped to 1,580, the value of your futures contract decreases to $50 * 1,580 = $79,000. After you return the $76,000 in leverage, you're left with $3,000, or a net loss of (3,000 - 4000)/(4000) = -25%. The math illustrates why using leverage increases your risk, but also increases your potential for return. Consider the first scenario, in which the index increases to 1,610. If you had forgone using margin and spent $80,000 of your own funds, your profit would be (80,500 - 80,000) / 80000 = .625%. This is smaller than your leveraged profit by a factor of 20, the inverse of the margin requirement (.625% / .05 = 12.5%). In this case, the use of leverage dramatically increased your rate of return.  However, in the case of a decrease, you spent $80,000, but gained $79,000, for a loss of only 1.25%. This is 20 times smaller in magnitude than your negative return when using leverage. By forgoing leverage, you've decreased your opportunity for upside, but also decreased your downside risk. 1) For futures contracts, the margin requirements are set by the exchange, which is CME group, in the case of the E-mini. The 5% in my example is higher than the actual margin requirement, which is currently $3,850 USD per contract, but it keeps the numbers simple. Also note that CME group refers to the initial margin as the performance bond instead. Your question is missing too much to be answered directly. Instead - here are some points to consider. Short term gains taxed at your marginal rates, whereas long term gains have preferable capital gains rates (up to 20% tax rate, instead of your marginal rate). So if you're selling at gain, you might want to consider to sell FIFO and pay lower capital gains tax rate instead of the short term marginal rate. If you're selling at loss and have other short term gains, you would probably be better selling LIFO, so that the loss could offset other short term gains that you might have.  If you're selling at loss and don't have short term gains to offset, you can still offset your long term gains with short term losses, but the tax benefit will be lower. In this case - FIFO might be a better choice again. If you're selling at loss, beware of the wash sale rules, as you might not be able to deduct the loss if you buy/sell within too short a window. I have found a good explanation here: http://www.contracts-for-difference.com/Financing-charge.html Financing is calculated by taking the overall position size, and multiplying it by (LIBOR + say 2%) and then dividing by 365 x the amount of days the position is open. For instance, the interest rate applicable for overnight long positions may be 6% or 0.06. To calculate how much it would cost you to hold a long position for X number of days you would need to make this 'pro rata' meaning that you would need to divide the 0.06 by 365 and multiply it by X days and then multiply this by the trade size. So for example, for a trade size of $20,000, held for 30 days, the interest cost would be about $98.6. It is important to note that due to financing, long positions held for extended periods can reduce returns. Looked at the luv model quickly. The most likely reason is you calculated a FCF lower than the market. You have FCF decreasing due to shrinking margins over the model period. Your terminal value then has the FCF growing by 2.3% into perpetuity so that doesn't really coincide. I mean, it could but I wouldn't use it. I personally think the shrinking margin assumption going forward is a little much.   For your terminal value calc, don't you want that to be the final model year cash flow times 1 plus the terminal growth rate?    Also, I find it interesting that the risk free rate is the terminal growth rate. Any particular reasoning behind that?  It works now at the 2.3% but probably wouldn't in a different interest rate environment. Thanks to this youtube video I think I understood the required calculation. Based on following notation: then the formula to find x is: I found afterwards an example on IB site (click on the link 'How to Determine the Last Stock Price Before We Begin to Liquidate the Position') that corroborate the formula above. If this is the initial transaction, the rules of a short margin account say that if you shorted 1000 share of ABC at $5/share your credit balance would be $5000 from the short plus you would have to put up yourself $5000 cash or $10,000 of marginal securities. So this is not really leveraging using margin. You have to put in just as much as the short generates. Is that what this relates to? Once the initial purchase has been made the minimum maintenance for a stock trading under $5 per share is 100% of the short market value in the margin account or $2.50 per share whichever is greater. For stock trading at $5/share or greater the minimum maintenance requirement is $5/share or 30% of the short market value, whichever is greater. The minimum maintenance requirements can be tighter.