Today’s midday gainers are Sarepta Therapeutics Inc (NASDAQ:SRPT), SolarCity Corp (NASDAQ:SCTY), Turquoise Hill Resources Ltd (NYSE:TRQ). The losers: Herbalife Ltd. (NYSE:HLF), BioFuel Energy Corp. (NASDAQ:BIOF) and ASML Holding N.V. (ADR) (NASDAQ:ASML).

Sarepta Therapeutics SPRT

Sarepta is today’s top performing stock

Topping off our midday gainers list this Thursday is Sarepta Therapeutics Inc (NASDAQ:SRPT), which shot up +33.13%. At the 32nd annual JP Morgan Healthcare Conference yesterday, Sarepta CEO Chris Garabedian updated investors on a couple of key issues surrounding the company’s Duchenne muscular dystrophy (DMD) pipeline.Billionaire George Soros owns 665,000 shares of the biopharmaceutical company, representing 0.34% of his portfolio. Soros first bought SRPT in September 2012 and has been increasing his position since then, paying an average price of $31.17 per asset.

Following Sarepta Therapeutics Inc. is SolarCity Corp (NASDAQ:SCTY). Its stock price hit $75.63 today, a +10.41% increase. Tiger Global holds 500,000 shares (0.29% of its portfolio), acquired at an average price of $36.89 each.

Third on the list is Turquoise Hill Resources Ltd (NYSE:TRQ), the stock price of which increased +9.04% to $3.86 today. Soros owns 3.9 million shares of the mining company (a 0.19% exposure). Another big player that owns TRQ is Ray Dalio, who holds 126,000 shares, bought for $6.76 each.

Midday Losers

It was a rough day for Herbalife Ltd. (NYSE:HLF), which dropped -7.89% to $73.04. Activist investor Carl Icahn owns almost 17 million shares of the company (a 4.81% exposure), and Soros holds five million assets (acquired at an average $42.72).

Second is ethanol producer BioFuel Energy Corp. (NASDAQ:BIOF). Its stock price decreased -5.02% today. With 1.04 million shares, Daniel Loeb is one of the billionaires tracked by iBillionaire with a position in BIOF. And David Einhorn holds 1.4 million assets.

Last but not least is ASML Holding N.V. (ADR) (NASDAQ:ASML), which dropped -4.55% to $85.31. Steve Mandel holds 1.02 million ASML shares (0.46% of his portfolio), acquied at an average price of $74.77.