In this video, Motley Fool health care analyst David Williamson gives us the story behind two big biotech jumps today and two big stumbles. Sequenom (NASDAQ: SQNM) continues its rally from Friday with more good news that its RetnaGene AMD accurately predicts the progression of wet age-related macular degeneration; this has shares up an additional 8% on top of Friday's 19%. Repros Therapeutics (NASDAQ: RPRX) also up today ahead of presenting both of its phase 2 drugs, Androxal and Proellex, at the Lazard conference tomorrow. Meanwhile, Cyclacel (NASDAQ: CYCC) and Transcept (NASDAQ: TSPT) are both down today after disappointing earnings releases.

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