** Shares of drugmaker Crinetics Pharmaceuticals CRNX.O jump 99.1% to $83.61 premarket

** Vertex Pharmaceuticals VRTX.O will buy CRNX for a total equity value of about $10 billion, the companies said late on Monday, adding treatments for rare hormonal diseases to its portfolio

** VRTX's offer of $85 per Crinetics share represents a 102% premium to the stock's Monday close, as per Reuters' calculations

** VRTX expects the deal to close in Q3 2026 and become accretive to adjusted operating income in 2029

** "Vertex remains ahead of the curve, where a possibly high-value Crinetics endocrine pipeline could yield meaningful returns in the medium-to-long term," BMO Capital Markets says

** As of last close, CRNX down 9.7% YTD