Marlboro Friday” refers to a day back in 1993 when Philip Morris (MO) announced drastic cuts in cigarette prices in order to better compete with the cheaper prices being offered by generic makers. As a result of the move, the company’s stock immediately dropped over 25%. Fast forwarding a quarter century, today could go down in the annals of history as ‘Biogen Thursday’ as the company announced that it was discontinuing trials for its experimental treatment of Alzheimer’s disease as the initial results have been ineffective. As a result of Biogen’s (BIIB) announcement, the stock, like MO back in 1993, has been trading down over 25%.

In the case of MO back in 1993, the stock did a whole lot of nothing for the next six months. From the initial decline on 4/2/1993, MO dropped an additional 10% over the following four weeks and then moved sideways through the Fall. From there, the stock generally trended higher and first briefly traded above its pre-Marlboro Friday levels on 10/27/94, but didn’t convincingly break above those levels until the following March, or nearly a full two years after the initial decline. While this morning was no doubt a painful one for BIIB shareholders, as was the case with Philip Morris in the early 1990s, the hope is that a little (or a lot depending on your level of patience) time will also heal the sting from today’s “Biogen Thursday”.

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