Silver Spring Networks Inc (NYSE:SSNI), Essent Group Ltd (NYSE:ESNT) and LipoScience Inc (NASDAQ:LPDX) are today’s top-gaining billionaire stock picks midday. Having a tough start to the week are Keryx Biopharmaceuticals (NASDAQ:KERX), Kamada Ltd (NASDAQ:KMDA) and Concho Resources Inc (NYSE:CXO).

Silver Spring Networks

Silver Spring Networks Climbs

Silver Spring Networks Inc (NYSE:SSNI) surged +10.57% early in the day this Monday. The stock has a consensus buy rating from the eight ratings firms currently covering it and is currently trading close to its 52-week low of $9.05. Billionaire hedge fund manager Richard Chilton has had a position in the grid networks and security technology solutions provider since the first quarter of 2013, and as of the second quarter of this year, he holds 166,000 shares.

Essent Group Ltd (NYSE:ESNT) hit midday up +9.05%, putting its 30-day gain at +13.09%. George Soros purchased 7.5 million ESNT shares during the fourth quarter of 2013 and has maintained his position through the second quarter of this year. ESNT is down -6.65% year-to-date.

LipoScience Inc (NASDAQ:LPDX) climbed +7.14% today and is up +17.67% over the past five days. The company develops and markets clinical diagnostic applications and is a Wilbur Ross investment pick.

Keryx Biopharmaceuticals Declines

Keryx Biopharmaceuticals (NASDAQ:KERX) slipped -10.1%. The company has received five negative revisions in recent weeks, and though the announcement was made on Friday that the FDA has approved one of its kidney drugs, investors remain unimpressed. Seth Klarman initiated a position in the company in Q1 2014 and as of Q2 holds 10.54 million KERX shares. Despite today’s dip, its price is still up +21% YTD.

Kamada Ltd (NASDAQ:KMDA) hit noon posting a -7.48% loss for the day. Its price has declined -22.56% in the past five days, and the company has taken a major hit following disappointing trial results revealed last week. Billionaire investor John Paulson initiated a 750,000-share position in the Israeli biopharmaceutical firm during the second quarter of last year.

Taking the last spot on today’s list of losers is Concho Resources Inc (NYSE:CXO), down -5.17% midday. Today, analysts at Raymond James dropped their price objective for the stock from $172.00 to $169.00, and news also emerged that one company executive sold off a number of his shares. Jorge Lemann, Richard Chilton and Ray Dalio have positions in the firm, which, despite today’s loss, is up +19.4% for the year.