老师，这道题还是不懂为什么要交两次155的佣金？第二次不是说买股票只收145么 ？

NO.PZ2023040301000027 问题如下 You ci to sell short 100 shares of Charlotte Horse Farms when it is selling its yearly high of 56. Your broker tells you thyour margin requirement is 45% anththe commission on the purchase is $155. While you are short the stock, Charlotte pays a $2.50 per share vin the enof one year, you buy 100 shares of Charlotte 45 to close out your position anare chargea commission of $145. Whis your rate of return on the investment? 20.56% B.22.65% C.18.56% Profit on a short sale = Begin value — Enng value — vin( Interest)— Trans. costsü Beginning value of investment = $56.00 x 100 =$5,600 (Solunr a short sale arrangement)ü Enng value of investment = $45.00 x 100=$4,500ü Transaction costs= $155 + $145 =$300.00ü vin = $2.50 x 100 shares =$250.00ü Profit= $5,600 — $4,500 — $250 — $300= $550.00Ø Initiinvestment = Margin requirement + Commission = (0.45 x $5,600) + $155= $2,520 + $155= $2,675The rate of return on your investment is 20.56%=$550.00 / $2,675 如题

NO.PZ2023040301000027 问题如下 You ci to sell short 100 shares of Charlotte Horse Farms when it is selling its yearly high of 56. Your broker tells you thyour margin requirement is 45% anththe commission on the purchase is $155. While you are short the stock, Charlotte pays a $2.50 per share vin the enof one year, you buy 100 shares of Charlotte 45 to close out your position anare chargea commission of $145. Whis your rate of return on the investment? 20.56% B.22.65% C.18.56% Profit on a short sale = Begin value — Enng value — vin( Interest)— Trans. costsü Beginning value of investment = $56.00 x 100 =$5,600 (Solunr a short sale arrangement)ü Enng value of investment = $45.00 x 100=$4,500ü Transaction costs= $155 + $145 =$300.00ü vin = $2.50 x 100 shares =$250.00ü Profit= $5,600 — $4,500 — $250 — $300= $550.00Ø Initiinvestment = Margin requirement + Commission = (0.45 x $5,600) + $155= $2,520 + $155= $2,675The rate of return on your investment is 20.56%=$550.00 / $2,675 请问老师我是否可以这样理解，在之前的一道问题中我们是拥有多头头寸，因此收益率的计算思路是用期末资产减去期初投入的自有资金然后再除以自由资金，这个过程中佣金已经被分别扣减了两次，但是是分散在两次计算过程中的，实际上利润也是扣减了两次的佣金；但在这道题中我们持有的是空头头寸，就是直接计算利润去除以期初的自有资金，不用再计算期末的资产，因此体现在计算过程中就是直接一次性扣减了两次的佣金，这样理解正确吗

NO.PZ2023040301000027问题如下 You ci to sell short 100 shares of Charlotte Horse Farms when it is selling its yearly high of 56. Your broker tells you thyour margin requirement is 45% anththe commission on the purchase is $155. While you are short the stock, Charlotte pays a $2.50 per share vin the enof one year, you buy 100 shares of Charlotte 45 to close out your position anare chargea commission of $145. Whis your rate of return on the investment? 20.56%B.22.65%C.18.56% Profit on a short sale = Begin value — Enng value — vin( Interest)— Trans. costsü Beginning value of investment = $56.00 x 100 =$5,600 (Solunr a short sale arrangement)ü Enng value of investment = $45.00 x 100=$4,500ü Transaction costs= $155 + $145 =$300.00ü vin = $2.50 x 100 shares =$250.00ü Profit= $5,600 — $4,500 — $250 — $300= $550.00Ø Initiinvestment = Margin requirement + Commission = (0.45 x $5,600) + $155= $2,520 + $155= $2,675The rate of return on your investment is 20.56%=$550.00 / $2,675 vin这个vin是投资者收到的分红吗，为什么收益里面不包括反而要扣除呢

NO.PZ2023040301000027 问题如下 You ci to sell short 100 shares of Charlotte Horse Farms when it is selling its yearly high of 56. Your broker tells you thyour margin requirement is 45% anththe commission on the purchase is $155. While you are short the stock, Charlotte pays a $2.50 per share vin the enof one year, you buy 100 shares of Charlotte 45 to close out your position anare chargea commission of $145. Whis your rate of return on the investment? 20.56% B.22.65% C.18.56% Profit on a short sale = Begin value — Enng value — vin( Interest)— Trans. costsü Beginning value of investment = $56.00 x 100 =$5,600 (Solunr a short sale arrangement)ü Enng value of investment = $45.00 x 100=$4,500ü Transaction costs= $155 + $145 =$300.00ü vin = $2.50 x 100 shares =$250.00ü Profit= $5,600 — $4,500 — $250 — $300= $550.00Ø Initiinvestment = Margin requirement + Commission = (0.45 x $5,600) + $155= $2,520 + $155= $2,675The rate of return on your investment is 20.56%=$550.00 / $2,675 老师，我是这么理解的期初买进给了1笔155的佣金，期末应该是买回股票归还，减去1笔145的佣金，为什么期末还需要减去1个买进股票155的佣金？

NO.PZ2023040301000027问题如下 You ci to sell short 100 shares of Charlotte Horse Farms when it is selling its yearly high of 56. Your broker tells you thyour margin requirement is 45% anththe commission on the purchase is $155. While you are short the stock, Charlotte pays a $2.50 per share vin the enof one year, you buy 100 shares of Charlotte 45 to close out your position anare chargea commission of $145. Whis your rate of return on the investment? 20.56%B.22.65%C.18.56% Profit on a short sale = Begin value — Enng value — vin( Interest)— Trans. costsü Beginning value of investment = $56.00 x 100 =$5,600 (Solunr a short sale arrangement)ü Enng value of investment = $45.00 x 100=$4,500ü Transaction costs= $155 + $145 =$300.00ü vin = $2.50 x 100 shares =$250.00ü Profit= $5,600 — $4,500 — $250 — $300= $550.00Ø Initiinvestment = Margin requirement + Commission = (0.45 x $5,600) + $155= $2,520 + $155= $2,675The rate of return on your investment is 20.56%=$550.00 / $2,675 155的佣金，为什么放在期末计算而不放在期初结算？