NEW YORK ( TheStreet) -- As much as I love this business of financial writing, there is nothing that I love more than being right.And I love telling you about it. But if you stay in the business long enough, you'll realize that every once in a while, a writer has to take it on the chin and admit that he was just flat-out wrong about a call. While I've never expected to nail every prediction with pinpoint accuracy, I can't say I've ever blown a call to the extent of Achillion Pharmaceuticals ( ACHN), a company that has now become a shell of itself, if not a complete disaster. Now, if you know anything about the biotech industry, it's extremely volatile. But this is a sector that moves quickly in either direction on the prospects on new drug production and the approval of regulators like the Food and Drug Administration (FDA). So back in July, following the stock's 25% drop on news that Sovaprevir, the company's lead protease inhibitor for hepatitis C (HCV) had been put on hold by the FDA due to safety concerns, I called it a buying opportunity. At the time, shares were trading around $6 after falling from well above $8. Fast-forward three months later: shares have just made a new 52-week low of $2.87 as of Monday's trading. With a close of $3.02 Monday, essentially from the time that Achillion began its selloff in July, the stock has now lost 64%, including falling 53% since my buy recommendation. Before we go into why the company is getting hammered this time, let's revisit my buy thesis from July. I'm not here to make any excuses because, clearly, I have no place to hide here. However, as I've noted, thick skin is required to be an investor in this sector. And to make any money at all (as the shorts are likely counting today), requires not only a significant amount of risk, but also an understanding of how these drugs come to market. It's not an easy process. In the July article, I said: I don't disagree that Achillion brings considerably more risk than a much improved Abbott Labs (ABT) or a powerhouse like Johnson & Johnson (JNJ). But after this recent 25% decline, Achillion's stock has become a bit more interesting, if not significantly undervalued.