Chris Lau, Kapitall: The ongoing decline in the S&P 500 index from its recent peak in May 2013 could be the fuel bears need to mount an even bigger bearish bet — and the pharmaceutical and biotechnology sector could provide a good hunting ground for those bears. (Similar lists: Insider Trends: 5 High Growth Healthcare Stocks With Heavy Insider Buying) The share price of companies could be bid up because investors foresee good times ahead. To find pharmaceutical companies with bearish bets against them, look at the short float. Chart source: Yahoo! Finance Given the following small-cap companies' double-digit short float, bears clearly expect them to decline. With characteristics like strong prescription growth, royalty income, or drugs to cure infection, can these companies overcome the bear attack? The companies have a market capitalization of between $635 million and $1.2 billion: 13.8% Prescription growth Amarin ( AMRN) is a biopharmaceutical company focused on improving cardiovascular health in patients. The short float is 16.63%. Amarin launched Vascepa on Jan. 28, 2013. The company recognized $2.34 million in sales during the first quarter ended March 31, 2013. More recently, Bloomberg Industries reported that prescriptions rose by 4% on the week ended May 24, and prescriptions are up an impressive 13.8% in the 4 weeks ended May 24. The company also reported positive results in patient studies taking Vascepa with a statin. Triglyceride levels declined by 21.5%, while LDL-C (low-density lipoprotein cholesterol), declined 6.2%. LDL-C is considered the “bad” cholesterol, so its reduction is a good indication for Vascepa. Despite the good news, it did not help Arena’s share price. Shares still continued to languish, trading in a range of between around $6.50 and $7. Competitive Worries AstraZeneca ( AZN) could be a threat to Amarin’s Vascepa. The company bought Omthera, a company that makes Epanova, which reduces triglyceride levels. Epanova does not have FDA approval, and has side effects. If Amarin’s Vascepa is viewed as superior, Amarin could get a positive review from the FDA. Infectious Diseases Shares in Idenix Pharmaaceuticals ( IDIX) drifted since the start of 2013, but is rising steadily again. The short float is 13.34%.The company focuses on infectious diseases, and is developing an antiviral, specifically the treatment of the hepatitis C virus. This 14 year old company has a market cap of just $693 million, despite having successfully brought drug for Hepatitus B virus to market with its partner, Novartis. The company spent a lot of time trying to understand the nucleotides involved in the virus. The intense research efforts led to the start of a trial announced on May 30, 2013. Idenix is starting a phase II clinical trial that will evaluate an all-oral direct-acting antiviral combination therapy. The study is being done in partnership (and non-exclusively) with Janssen. Income from Royalties PDL BioPharma ( PDLI) generates substantial revenue from royalties. The short float is 18.64%.In the first quarter of 2013, the company grew its royalty revenues by 19% compared to the previous year. PDL generated $91.8 million in revenues in the first quarter. The company has $187.2 million in cash and equivalents, as at March 31, 2013. Royalty revenues grew fastest from Avastin, a drug used to treat metastatic colorectal cancer, metastatic kidney cancer, Glioblastoma, and lung cancer. The company has a strong history of looking out for shareholder returns. Dividend payments this year will be $0.60 per share, which yields 7.6% annually.