There's reason to be optimistic about what's to come.You might expect Eli Lilly (LLY -3.36%) to perform as big pharma companies often do: offering progressive earnings gains that translate into a steady increase for the stock over the long term. But in recent times, Lilly hasn't exactly behaved like a slow and steady healthcare player, and instead has taken the path of a fast-moving growth stock.Lilly has jumped about 230% over three years and more than 75% over the past year. The driver of these gains is e ...