Question

麻烦帮忙翻译成英文，不要电脑翻译的，拜托。非常感谢。

布莱克-斯科尔斯模型优点是计算较为简单，定价较为合理可靠。在实务中，当实际情形与模型的严格假设条件不一致时，只需对模型做简单的调整即可加以应用。无需采用更加复杂的定价模型，所以得到广泛应用。
布莱克-斯科尔斯模型缺点是：首先，交易成本的假设。B-S模型假定交易成本为0，可以连续进行动态的套期保值，从而保证无风险组合的存在和期权定价的正确性。但事实上，交易成本总是客观存在的，这使得投资者无法以所希望的频率进行套期保值，同时，对理论上可行的价格以及其预期收益，考虑了交易成本之后就无法实现；其次，波动率为常数的假设。B-S模型假定标的资产的波动率是一个已知的常数或者是一个确定的已知函数，这一点在标的资产价格的实证检验中被否定，期权市场本身反映的隐含波动率也提出了相反的证据。实际上，波动率本身就是一个随机变量；再次，不确定的参数。B-S模型假定波动率、利率、股利等参数都是已知的常数或者是已知的确定函数。但事实上，他们都不是一个常数，甚至对时间和标的资产的价格而言，也不是一个确定的函数，波动率甚至完全无法在市场上观察到，也无法预测；最后，资产价格的连续变动。B-S模型假定标的资产的价格是连续变动的且服从对数正态分布。然而，在现实市场中，不连续是常见的，资产价格常常跳跃，并且经常是向下跳跃，这在对数正态分布的资产定价模型中并没有体现出来，对于正正态分布来说，这些突然变动的幅度太大，发生太过频繁；同时，由于跳跃来得太突然，这使得无法单纯依靠对数正态扩散模型对它们进行动态保值。因此，这需要在模型中考虑跳跃的情形，同时也需要考察在极端变动的情况下可能导致的最差结果。

Answer 1

Black - Scholes model has the advantages of simple calculation, pricing is reasonable and reliable. In practice, the strict assumptions when the actual situation and the model is not consistent, need only be applied on the model of adjustment can be simple. Without the use of pricing model is more complex, so are widely used.
Black - Scholes model is: first, the transaction cost hypothesis. The B-S model assumes that the transaction cost is 0, continuously dynamic hedging, so as to ensure the correctness of the risk-free portfolio and option pricing. But in fact, the transaction cost is always an objective existence, which makes investors not to hedge, at the desired frequency and at the same time, the theory of price and the expected return, after considering transaction costs can not be achieved; secondly, the volatility is constant false. The B-S model assumes that the underlying asset volatility is a known constant or a known function identified, denied this point empirically in the underlying asset price inspection, option market itself reflects the implied volatility is also presented evidence to the contrary. In fact, volatility is itself a random variable; thirdly, uncertain parameters. The B-S model assumes that the volatility, interest, dividends and other parameters are known constants or determine the function of known. But in fact, they are not a constant, even to the time and the price of the underlying asset, not a deterministic function, volatility and even cannot be observed in the market, also cannot be predicted; finally, continuous asset price changes. The B-S model assumes that the price of the underlying asset is a continuous variable and lognormal distribution. However, in the real market, discontinuities are common, often jump in asset prices, and often is, this is not reflected in the asset pricing model of log-normal distribution, the normal distribution, the sudden change of too much, too frequent occurrence; at the same time, because the jump come too suddenly, making it impossible to rely solely on the lognormal diffusion model for dynamic hedging on them. Therefore, it needs to consider jumping in the model, but also need to examine the difference results in extreme changes may lead to.

Answer 2

Black-scholes model advantage is calculation is relatively simple, the pricing is reasonable and reliable. In practice, when the actual situation and the model of strict assumptions do not agree, just a model to do a simple adjustment can be applied. Don't need to use more complex pricing model, so widely used. Black-scholes model shortcomings are: first, transaction cost hypothesis. B - S model assumes that the transaction cost is zero, can be continuous dynamic hedging, to ensure the correctness of the existence of the risk-free portfolio and option pricing. But, in fact, the transaction cost is objective existence, which makes investors cannot frequency hedging to want, at the same time, the price of theoretically possible and its expected returns, and consider the transaction cost
纯手打 望楼主采纳

Answer 3

你在这上面问市徒劳，不会有人花3小时的时间来帮你的。