NEW YORK ( TheStreet) -- Siga Technologies (Nasdaq: SIGA) is trading at unusually high volume Tuesday with 1.4 million shares changing hands. It is currently at 4.1 times its average daily volume and trading up $2.26 (+19.9%) at $13.66 as of 12:47 p.m. ET. Siga has a market cap of $546.2 million and is part of the health care sector and drugs industry. Shares are down 18.6% year to date as of the close of trading on Friday. SIGA Technologies, Inc., a bio-defense company, engages in the discovery, development, and commercialization of products for use in defense against biological warfare agents comprising smallpox and arenaviruses. TheStreet Ratings rates Siga as a hold. The company's strengths can be seen in multiple areas, such as its robust revenue growth, largely solid financial position with reasonable debt levels by most measures and solid stock price performance. However, as a counter to these strengths, we also find weaknesses including unimpressive growth in net income, weak operating cash flow and feeble growth in the company's earnings per share. You can view the full Siga Ratings Report. See all heavy volume stocks in our stocks moving on unusual volume list or get investment ideas from our investment research center.