Market Overview

Short Interest Surges In Illumina And Vertex Pharmaceuticals

Short Interest Surges In Illumina And Vertex Pharmaceuticals
  • Short interest in many of the leading biotech stocks shrank in the most recent period.
  • Two stocks in particular stood out among the few that bucked the trend in those two weeks.
  • Shares of one of those two stocks slumped more than 22 percent during the period.

Short sellers shied away from many of the leading biotechnology stocks as the markets reached new highs in late April. However, a few stocks in the industry bucked that trend between the April 15 and April 29 settlement dates.

Illumina, Inc. (NASDAQ: ILMN) and Vertex Pharmaceuticals Incorporated (NASDAQ: VRTX) in particular saw double-digit percentage increases in the number of their shares short, in a period in which the former posted disappointing preliminary first-quarter results and shares of the latter struggled to recover from a disastrous first quarter.

Others that saw more modest rises in short interest include Gilead Sciences and Incyte, while the number of shares short in BioMarin Pharmaceutical, Medivation and Opko Health hardly changed at all between the settlement dates. The final weeks of the month brought shrinking numbers of shares short at Acadia Pharmaceuticals, Alexion Pharmaceuticals, Amgen, Baxalta, Biogen, Celgene, Juno Therapeutics and Seattle Genetics.

Below is a quick look at how Illumina and Vertex have fared recently and what analysts expect from them.

Related Link: Short Sellers Dump Amgen And Baxalta


This San Diego-based maker of products and services that serve the sequencing, genotyping and gene expression markets saw its short interest jump almost 11 percent to more than 6.60 million shares, or 4.6 percent of float, in the final weeks of the month. That ended nine straight periods in which the number of its shares short pulled back. It would take less than three days to cover all short positions.

Illumina posted disappointing preliminary first-quarter results in the period, resulting in downgrades. Short sellers watched the shares fall more than 22 percent during the two-week short interest period, compared to a decline of more than 3 percent in the Nasdaq.

Vertex Pharmaceuticals

The number of shares sold short in this company focused on cystic fibrosis and other serious diseases surged more than 12 percent late in the month to more than 5.65 million, or 2.3 percent of the float. That ended three consecutive periods of falling short interest. The days to cover rose to more than two as the average daily volume dwindled somewhat.

Vertex stock has struggled since last summer and was one of the worst performers in the first quarter. Shares ended the latest short interest period up about 3 percent, though they were up 6 percent twice in those two weeks. The stock now is almost 35 percent lower since the beginning of the year.

Disclosure: At the time of this writing, the author had no position in the mentioned equities.


Related Articles (ILMN + VRTX)

View Comments and Join the Discussion!

Posted-In: ACADIA Pharmaceuticals Alexion Pharmaceuticals amgen BaxaltaBiotech Short Ideas Trading Ideas General Best of Benzinga