Existence of Unbiased Estimators of the Black/Scholes Option Price, Other Derivatives, and Hedge Ratios
重新审视经典布莱克/斯科尔斯期权价格中因使用历史方差导致的统计偏差问题，发现只有平价期权才能得到无偏估计。
In this paper, we reexamine the question of statistical bias in the classic Black/Scholes option price where randomness is due to the use of the historical variance. We show that the only unbiased estimated option is an at the money option.