金融工程习题课(三)

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期货市场

  1. Suppose that you enter into a short futures contract to sell July silver for $17.20 per ounce. The size of the contract is 5,000 ounces. The initial margin is $4,000, and the maintenance margin is $3,000. What change in the futures price will lead to a margin call? What happens if you do not meet the margin call?


  2. Suppose that in September 2021 a company takes a long position in a contract on May 2022 crude oil futures. It closes out its position in March 2022. The futures price (per barrel) is $48.30 when it enters into the contract, $50.50 when it closes out its position, and $49.10 at the end of December 2021. One contract is for the delivery of 1,000 barrels. What is the company’s total profit? When is it realized? How is it taxed if it is (a) a hedger and (b) a speculator? Assume that the company has a December 31 year end.


  3. What does a stop order to sell at $2 mean? When might it be used? What does a limit order to sell at $2 mean? When might it be used?


  4. The party with a short position in a futures contract sometimes has options as to the precise asset that will be delivered, where delivery will take place, when delivery will take place, and so on. Do these options increase or decrease the futures price? Explain your reasoning.


  5. Explain how margin accounts protect futures traders against the possibility of default.


  6. A trader buys two July futures contracts on frozen orange juice concentrate. Each contract is for the delivery of 15,000 pounds. The current futures price is 160 cents per pound, the initial margin is $6,000 per contract, and the maintenance margin is $4,500 per contract. What price change would lead to a margin call? Under what circumstances could $2,000 be withdrawn from the margin account?


  7. Show that, if the futures price of a commodity is greater than the spot price during the delivery period, then there is an arbitrage opportunity. Does an arbitrage opportunity exist if the futures price is less than the spot price? Explain your answer.


  8. Explain what a stop–limit order to sell at 20.30 with a limit of 20.10 means.


  9. At the end of one day a clearing house member is long 100 contracts, and the settlement price is $50,000 per contract. The original margin is $2,000 per contract. On the following day the member becomes responsible for clearing an additional 20 long contracts, entered into at a price of $51,000 per contract. The settlement price at the end of this day is $50,200. How much does the member have to add to its margin account with the exchange clearing house?


  10. “Speculation in futures markets is pure gambling. It is not in the public interest to allow speculators to trade on a futures exchange.” Discuss this viewpoint.


  11. What do you think would happen if an exchange started trading a contract in which the quality of the underlying asset was incompletely specified?


  12. “When a futures contract is traded on the floor of the exchange, it may be the case that the open interest increases by one, stays the same, or decreases by one.” Explain this statement.


  13. A cattle farmer expects to have 120,000 pounds of live cattle to sell in 3 months. The live cattle futures contract traded by the CME Group is for the delivery of 40,000 pounds of cattle. How can the farmer use the contract for hedging? From the farmer’s viewpoint, what are the pros and cons of hedging?


  14. It is July 2021. A mining company has just discovered a small deposit of gold. It will take 6 months to construct the mine. The gold will then be extracted on a more or less continuous basis for 1 year. Futures contracts on gold are available with delivery months every 2 months from August 2021 to December 2022. Each contract is for the delivery of 100 ounces. Discuss how the mining company might use futures markets for hedging.


  15. Trader A enters into futures contracts to buy 1 million euros for 1.1 million dollars in three months. Trader B enters in a forward contract to do the same thing. The exchange rate (dollars per euro) declines sharply during the first two months and then increases for the third month to close at 1.1300. Ignoring daily settlement, what is the total profit of each trader? When the impact of daily settlement is taken into account, which trader has done better?


  16. Explain what is meant by open interest. Why does the open interest usually decline during the month preceding the delivery month? On a particular day, there were 2,000 trades in a particular futures contract. This means that there were 2,000 buyers (going long) and 2,000 sellers (going short). Of the 2,000 buyers, 1,400 were closing out positions and 600 were entering into new positions. Of the 2,000 sellers, 1,200 were closing out positions and 800 were entering into new positions. What is the impact of the day’s trading on open interest?


  17. A company enters into a short futures contract to sell 5,000 bushels of wheat for 750 cents per bushel. The initial margin is $3,000 and the maintenance margin is $2,000. What price change would lead to a margin call? Under what circumstances could $1,500 be with-drawn from the margin account?


  18. Suppose that there are no storage costs for crude oil and the interest rate for borrowing or lending is 4% per annum. How could you make money if the June and December futures contracts for a particular year trade at $50 and $56, respectively?


  19. What position is equivalent to a long forward contract to buy an asset at K on a certain date and a put option to sell it for K on that date.


  20. A bank’s derivatives transactions with a counterparty are worth +10 million to the bank and are cleared bilaterally. The counterparty has posted $10 million of cash collateral. What credit exposure does the bank have?

用期货合约对冲风险

  1. Explain what is meant by a perfect hedge. Does a perfect hedge always lead to a better outcome than an imperfect hedge? Explain your answer.


  2. Under what circumstances does a minimum variance hedge portfolio lead to no hedging at all?


  3. Suppose that the standard deviation of quarterly changes in the prices of a commodity is $0.65, the standard deviation of quarterly changes in a futures price on the commodity is $0.81, and the coefficient of correlation between the two changes is 0.8. What is the optimal hedge ratio for a 3-month contract? What does it mean?


  4. A company has a $20 million portfolio with a beta of 1.2. It would like to use futures contracts on a stock index to hedge its risk. The index futures price is currently standing at 1080, and each contract is for delivery of $250 times the index. What is the hedge that minimizes risk? What should the company do if it wants to reduce the beta of the
    portfolio to 0.6?


  5. In the corn futures contract traded on an exchange, the following delivery months are available: March, May, July, September, and December. Which of the available contracts should be used for hedging when the expiration of the hedge is in (a) June, (b) July, and (c) January.


  6. Does a perfect hedge always succeed in locking in the current spot price of an asset for a future transaction? Explain your answer.


  7. Explain why a short hedger’s position improves when the basis strengthens unexpectedly and worsens when the basis weakens unexpectedly.


  8. “If the minimum variance hedge ratio is calculated as 1.0, the hedge must be perfect.” Is this statement true? Explain your answer.


  9. “If there is no basis risk, the minimum variance hedge ratio is always 1.0.” Is this statement true? Explain your answer.


  10. “When the futures price of an asset is less than the spot price, long hedges are likely to be particularly attractive.” Explain this statement.


  11. The standard deviation of monthly changes in the spot price of live cattle is (in cents per pound) 1.2. The standard deviation of monthly changes in the futures price of live cattle for the closest contract is 1.4. The correlation between the futures price changes and the spot price changes is 0.7. It is now October 15. A beef producer is committed to
    purchasing 200,000 pounds of live cattle on November 15. The producer wants to use the December live cattle futures contracts to hedge its risk. Each contract is for the delivery of 40,000 pounds of cattle. What strategy should the beef producer follow?


  12. A corn farmer argues “I do not use futures contracts for hedging. My real risk is not the price of corn. It is that my whole crop gets wiped out by the weather.” Discuss this viewpoint. Should the farmer estimate his or her expected production of corn and hedge to try to lock in a price for expected production?


  13. On July 1, an investor holds 50,000 shares of a certain stock. The market price is 30pershare.Theinvestorisinterestedinhedgingagainstmovementsinthemarketoverthenextmonthanddecidestouseanindexfuturescontract.Theindexfuturespriceiscurrently1,500andonecontractisfordeliveryof30 per share. The investor is interested in hedging against movements in the market over the next month and decides to use an index futures contract. The index futures price is currently 1,500 and one contract is for delivery of50 times the index. The beta of the stock is 1.3. What strategy should the investor follow? Under what circumstances will it be profitable?


  14. An airline executive has argued: “There is no point in our using oil futures. There is just as much chance that the price of oil in the future will be less than the futures price as there is that it will be greater than this price.” Discuss the executive’s viewpoint.


  15. Suppose that the 1-year gold lease rate is 1.5% and the 1-year risk-free rate is 5.0%. Both rates are compounded annually. Use the discussion in Business Snapshot 3.1 to calculate the maximum 1-year gold forward price Goldman Sachs should quote to the gold-mining company when the spot price is $1,200.


  16. The expected return on the S&P 500 is 12% and the risk-free rate is 5%. What is the expected return on an investment with a beta of (a) 0.2, (b) 0.5, and (c) 1.4?


  17. It is now June. A company knows that it will sell 5,000 barrels of crude oil in September. It uses the October CME Group futures contract to hedge the price it will receive. Each contract is on 1,000 barrels of “light sweet crude.” What position should it take? What price risks is it still exposed to after taking the position?


  18. Sixty futures contracts are used to hedge an exposure to the price of silver. Each futures contract is on 5,000 ounces of silver. At the time the hedge is closed out, the basis is $0.20per ounce. What is the effect of the basis on the hedger’s financial position if (a) the trader
    is hedging the purchase of silver and (b) the trader is hedging the sale of silver?


  19. A trader owns 55,000 units of a particular asset and decides to hedge the value of her position with futures contracts on another related asset. Each futures contract is on 5,000 units. The spot price of the asset that is owned is $28 and the standard deviation of the change in this price over the life of the hedge is estimated to be $0.43. The futures price of the related asset is $27 and the standard deviation of the change in this over the life of the hedge is $0.40. The coefficient of correlation between the spot price change and futures price change is 0.95.
    (a) What is the minimum variance hedge ratio?
    (b) Should the hedger take a long or short futures position?
    (c) What is the optimal number of futures contracts when adjustments for daily settle-ment are not considered?
    (d) How can the daily settlement of futures contracts be taken into account?


  20. A company wishes to hedge its exposure to a new fuel whose price changes have a 0.6 correlation with gasoline futures price changes. The company will lose $1 million for each 1 cent increase in the price per gallon of the new fuel over the next three months. The new fuel’s price changes have a standard deviation that is 50% greater than price changes in gasoline futures prices. If gasoline futures are used to hedge the exposure, what should the hedge ratio be? What is the company’s exposure measured in gallons of the new fuel? What position, measured in gallons, should the company take in gasoline futures? How many gasoline futures contracts should be traded? Each contract is on 42,000 gallons.


  21. A portfolio manager has maintained an actively managed portfolio with a beta of 0.2. During the last year, the risk-free rate was 5% and equities performed very badly providing a return of -30,. The portfolio manager produced a return of -10, and claims that in the circumstances it was a good performance. Discuss this claim.


  22. It is July 16. A company has a portfolio of stocks worth $100 million. The beta of the portfolio is 1.2. The company would like to use the December futures contract on a stock index to change the beta of the portfolio to 0.5 during the period July 16 to November 16. The index futures price is currently 2,000 and each contract is on $250 times the index.
    (a) What position should the company take?
    (b) Suppose that the company changes its mind and decides to increase the beta of the portfolio from 1.2 to 1.5. What position in futures contracts should it take?

远期/期货定价

  1. What is the difference between the forward price and the value of a forward contract?


  2. Suppose that you enter into a 6-month forward contract on a non-dividend-paying stock when the stock price is $30 and the risk-free interest rate (with continuous compounding) is 5% per annum. What is the forward price?


  3. A stock index currently stands at 350. The risk-free interest rate is 4% per annum (with continuous compounding) and the dividend yield on the index is 3% per annum. What should the futures price for a 4-month contract be?


  4. Explain carefully why the futures price of gold can be calculated from its spot price and other observable variables whereas the futures price of copper cannot.


  5. Explain why a foreign currency can be treated as an asset providing a known yield.


  6. Is the futures price of a stock index greater than or less than the expected future value of the index? Explain your answer.


  7. A 1-year long forward contract on a non-dividend-paying stock is entered into when the stock price is 40andtheriskfreerateofinterestis5(a)Whataretheforwardpriceandtheinitialvalueoftheforwardcontract?(b)Sixmonthslater,thepriceofthestockis40 and the risk-free rate of interest is 5% per annum with continuous compounding. (a) What are the forward price and the initial value of the forward contract? (b) Six months later, the price of the stock is45 and the risk-free interest rate is still 5%. What are the forward price and the value of the forward contract?


  8. The risk-free rate of interest is 7% per annum with continuous compounding, and the dividend yield on a stock index is 3.2% per annum. The current value of the index is 150. What is the 6-month futures price?


  9. Assume that the risk-free interest rate is 4% per annum with continuous compounding and that the dividend yield on a stock index varies throughout the year. In February, May, August, and November, dividends are paid at a rate of 5% per annum. In other months, dividends are paid at a rate of 2% per annum. Suppose that the value of the index
    on July 31 is 1,300. What is the futures price for a contract deliverable in December 31 of the same year?


  10. Suppose that the risk-free interest rate is 6% per annum with continuous compounding and that the dividend yield on a stock index is 4% per annum. The index is standing at 400, and the futures price for a contract deliverable in four months is 405. What arbitrage opportunities does this create?


  11. The 2-month interest rates in Switzerland and the United States are, respectively, 1% and 2% per annum with continuous compounding. The spot price of the Swiss franc is $1.0500. The futures price for a contract deliverable in 2 months is $1.0500. What arbitrage opportunities does this create?


  12. The spot price of silver is $25 per ounce. The storage costs are $0.24 per ounce per year payable quarterly in advance. Assuming that interest rates are 5% per annum for all maturities, calculate the futures price of silver for delivery in 9 months.


  13. Suppose that F1F_1 and F2F_2 are two futures contracts on the same commodity with times to maturity, t1t_1 and t2t_2, where t2>t1t_2> t_1. Prove that F2F1er(t2t1)F_2\leq F_1e^{r(t_2-t_1)}, where rr is the interest rate(assumed constant) and there are no storage costs. For the purposes of this problem, assume that a futures contract is the same as a forward contract.


  14. When a known future cash outflow in a foreign currency is hedged by a company using a forward contract, there is no foreign exchange risk. When it is hedged using futures contracts, the daily settlement process does leave the company exposed to some risk. Explain the nature of this risk. In particular, consider whether the company is better off
    using a futures contract or a forward contract when:
    (a) The value of the foreign currency falls rapidly during the life of the contract.
    (b) The value of the foreign currency rises rapidly during the life of the contract.
    (c) The value of the foreign currency first rises and then falls back to its initial value.
    (d) The value of the foreign currency first falls and then rises back to its initial value. Assume that the forward price equals the futures price.


  15. It is sometimes argued that a forward exchange rate is an unbiased predictor of future exchange rates. Under what circumstances is this so?


  16. Show that the growth rate in an index futures price equals the excess return on the portfolio underlying the index over the risk-free rate. Assume that the risk-free interest rate and the dividend yield are constant.


  17. Explain carefully what is meant by the expected price of a commodity on a particular future date. Suppose that the futures price for crude oil declines with the maturity of the contract at the rate of 2% per year. Assume that speculators tend to be short crude oil futures and hedgers tend to be long. What does the Keynes and Hicks argument imply
    about the expected future price of oil?


  18. A U.S. company is interested in using the futures contracts traded by the CME Group to hedge its Australian dollar exposure. Define rr as the interest rate (all maturities) on the U.S. dollar and rfr_f as the interest rate (all maturities) on the Australian dollar. Assume that rr and rfr_f are constant and that the company uses a contract expiring at time TT to
    hedge an exposure at time t(T>t)t(T>t).
    (a) Show that the optimal hedge ratio is e(rfr)(Tt)e^{(r_f-r)(T-t)}, ignoring daily settlement.
    (b) Show that, when tt is 1 day, the optimal hedge ratio is almost exactly S0/F0S_0/F_0, where S0S_0 is the current spot price of the currency and F0F_0 is the current futures price of the currency for the contract maturing at time TT.
    (c) Show that the company can take account of the daily settlement of futures contracts for a hedge that lasts longer than 1 day by adjusting the hedge ratio so that it always equals the spot price of the currency divided by the futures price of the currency.


  19. What is the cost of carry for:
    (a) a non-dividend-paying stock
    (b) a stock index
    (c) a commodity with storage costs
    (d) a foreign currency


  20. The spot exchange rate between the Swiss franc and U.S. dollar is 1.0404 ($ per franc). Interest rates in the United States and Switzerland are 0.25% and 0% per annum, respectively, with continuous compounding. The 3-month forward exchange rate was 1.0300 ($ per franc). What arbitrage strategy was possible? How does your answer change if the forward exchange rate is 1.0500 ($ per franc).


  21. An index is 1,200. The three-month risk-free rate is 3% per annum and the dividend yield over the next three months is 1.2% per annum. The six-month risk-free rate is 3.5% per annum and the dividend yield over the next six months is 1% per annum. Estimate the futures price of the index for three-month and six-month contracts. All interest rates and
    dividend yields are continuously compounded.


  22. Suppose the current USD/euro exchange rate is 1.2000 dollar per euro. The six-month forward exchange rate is 1.1950. The six-month USD interest rate is 1% per annum continuously compounded. Estimate the six-month euro interest rate.


  23. The spot price of oil is $50 per barrel and the cost of storing a barrel of oil for one year is $3, payable at the end of the year. The risk-free interest rate is 5% per annum continuously compounded. What is an upper bound for the one-year futures price of oil?


  24. A company that is uncertain about the exact date when it will pay or receive a foreign currency may try to negotiate with its bank a forward contract that specifies a period during which delivery can be made. The company wants to reserve the right to choose the exact delivery date to fit in with its own cash flows. Put yourself in the position of the bank. How would you price the product that the company wants?


  25. A company enters into a forward contract with a bank to sell a foreign currency for K1K_1 at time T1T_1. The exchange rate at time T1T_1 proves to be S1(>K1)S_1(>K_1). The company asks the bank if it can roll the contract forward until time T2(>T1)T_2(>T_1) rather than settle at time T1T_1. The bank agrees to a new delivery price, K2K_2. Explain how K2K_2 should be calculated.