Note: This blog post previously analyzed Damien Challet's 'Sharper estimator' of the Signal-Noise Ratio. In a series of blog posts, I had found that the implementation of this estimator appeared to be biased, giving perhaps illusory gains in efficiency. I had noted in this post that I contacted Challet to present my concerns about his code. Since the time I wrote that post, Challet updated his sharpeRratio, package to version 1.2. We will perform an investigation of the fixed drawdown estimator, and link to it here.