In the last year, Dexcom Inc., of San Diego, has seen its market cap grow exponentially – from less than $5 billion in February 2018 to roughly $12.5 billion now. That followed about three years of stagnant valuation for the continuous glucose monitor (CGM) player. The strength of the recent Dexcom run-up has been on the thesis of widespread U.S. market penetration, particularly as it became the first CGM player to gain Medicare reimbursement.