Vertex Pharmaceuticals ( VRTX 3.06%) might be one of those special cases. Should you buy Vertex stock hand over fist before Jan. 30? What's so special about Jan. 30 for Vertex? It's the PDUFA action date set by the U.S. Food and Drug Administration (FDA) for making an approval decision on suzetrigine in treating acute pain.

Vertex Pharmaceuticals Inc. closed 19.80% below its 52-week high of $519.88, which the company reached on November 8th.