Sarepta Therapeutics Inc. SRPT was a star performer in Tuesday’s trading session, as the stock skyrocketed as much as 57.7% to a new high of $176.50 but closed a little lower, rising 36.8% (read: 4 Sector ETFs That Crushed S&P 500 in 9-Year Bull Run).The surge propelled the company’s market cap from $6.9 billion to more than $9 billion, making it the fifth most valuable drugmaker headquartered in Massachusetts, behind Biogen BIIB, Vertex Pharmaceuticals VRTX, Alexion Pharmaceuticals ALXN and Alnylam Pharmaceuticals ALNY.The massive gain for the mid-cap biotech firm came from encouraging early trial results for a gene therapy for Duchenne muscular dystrophy (DMD). The study was conducted on three patients and revealed an average reduction of more than 87% in their creatine kinase, an enzyme found within muscle cells that can leak into the bloodstream when damage has occurred in the muscle, on day 60.This indicates that Sarepta’s muscular dystrophy drug could successfully treat and produce robust levels of dystrophin, a protein that protects muscle cells.DMD is a rare genetic disease marked by progressive muscle degeneration, which can cause physical disability along with life-threatening problems in the heart and respiratory system. The disease mostly affects boys between the ages of 3 and 5, and typically kills patients before the age of 30.The positive clinical trial also sent shares of fellow DMD gene therapy developer Solid Biosciences SLDB up by more than 46% yesterday (see: all the Healthcare ETFs here).ETF ImpactThe news led to a surge in biotech ETFs, especially Virtus LifeSci Biotech Products ETF BBP, iShares Nasdaq Biotechnology ETF IBB andSPDR S&P Biotech ETF XBI. The trio has risen 2.3%, 1.5% and 1.4%, respectively. In fact, BBP and XBI touched a new 52-week high each.BBP in FoucsThe ETF follows the LifeSci Biotechnology Products Index, which measures the performance of biotechnology companies with a primary product offering or product candidate that has received the U.S. Food and Drug Administration’s approval. Holding 40 stocks, Sarepta Therapeutics takes the fourth position in the basket with a 4.1% share. The product has accumulated AUM of about $33.2 million and charges 79 bps in fees per year. It has a Zacks ETF Rank #2 (Buy) with a High risk outlook.IBB in FocusThis fund provides exposure to 192 firms by tracking the Nasdaq Biotechnology Index, with Sarepta accounting for 0.9% of assets. IBB is the most popular fund is the biotech space with AUM of $8.9 billion. Expense ratio comes in at 0.47%. IBB has a Zacks ETF Rank #3 (Hold) with a High risk outlook (read: Why These Small Cap Biotech ETFs are Soaring).XBI in FocusWith AUM of $5.3 billion, XBI provides equal-weight exposure across 120 stocks by tracking the S&P Biotechnology Select Industry Index. Sarepta is the seventh firm in the fund’s portfolio, making up for 1.4% share. XBI has 0.35% in expense ratio and a Zacks ETF Rank #3 with a High risk outlook.Bottom LineIn fact, these three ETFs clearly outpaced the other products in the biotech space in the last trading session. ALPS Medical Breakthroughs ETF SBIO and Virtus LifeSci Biotech Clinical Trials ETF BBC added just 0.5% each on the day as these products have no exposure to Sarepta Therapeutics.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ISHARES NDQ BIO (IBB): ETF Research Reports BIOSH-BIO CLNCL (BBC): ETF Research Reports BIOSH-BIO PRD (BBP): ETF Research Reports SPDR-SP BIOTECH (XBI): ETF Research Reports ALPS-MED BRKTH (SBIO): ETF Research Reports Alexion Pharmaceuticals, Inc. (ALXN): Free Stock Analysis Report Vertex Pharmaceuticals Incorporated (VRTX): Free Stock Analysis Report Alnylam Pharmaceuticals, Inc. (ALNY): Free Stock Analysis Report Biogen Inc. (BIIB): Free Stock Analysis Report Sarepta Therapeutics, Inc. (SRPT): Free Stock Analysis Report Solid Biosciences Inc. (SLDB): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report