Shares of Dyax Corp. (NasdaqGS: DYAX) surged nearly 50% during Tuesday’s after-hours session after the Massachusetts-based company said an early stage trial of its treatment for hereditary angioedema proved safe for use and effective in reducing extreme swelling attacks.

Dyax also announced receipt of Fast Track designation from the U.S. Food and Drug Administration (FDA) for the investigation of DX-2930 hereditary angioedema (HAE) attacks, according to a statement issued by the company.

Dyax closed with a market value of just under $2.3 billion Tuesday, so the stock is not a significant holding in some of the largest biotechnology exchange traded funds, but a few ETFs could benefit from a Wednesday surge for shares of Dyax.

The $534.4 million PowerShares Dynamic Biotechnology & Genome Portfolio (NYSEArca: PBE) has a weight of nearly 3% to Dyax, making the stock the ETF’s 12th-largest holding. PBE, which is coming off a first-quarter gain of nearly 10%, tracks an index evaluates companies for inclusion based on “price momentum, earnings momentum, quality, management action, and value,” according to PowerShares. [More M&A Spotlights Biotech ETFs]

Like many of its rivals, PBE has found itself front and center for plenty of good biotech cheer over the past year. The ETF has benefited from the acquisitions of Idenix Pharmaceuticals, InterMune and, most recently, Pharmacyclics (NasdaqGS: PCYC). PBE’s 3% weight to Dyax makes it one of the largest ETF holders of the stock.

The BioShares Biotechnology Products Fund (NasdaqGM: BBP), which debuted in December, features Dyax as its 16th-largest holding. BBP tracks an index follows U.S.-listed biotech companies with a primary product offering or product candidate that has landed FDA approval. The new ETF has impressed this year, notching a gain of almost 19%, one of the best showings among biotech ETFs. Additionally, over 20% of BBP’s roughly 35 holdings have been mentioned as potential takeover targets. [Unique Biotech ETFs Debut]