Livent (NYSE: LTHM) stock was already on a roll after it announced bumper numbers earlier this month. Livent is now merging with another lithium company, and the combined entity will be worth $10 billion and own one of the world's largest lithium deposit bases, positioning itself as a leading battery-grade lithium supplier. The merger announcement, coupled with a rebound in lithium prices, sent shares of Livent higher this week: The lithium stock had clocked 11.7% gains at its highest point during the week as of 10 a.m. ET Friday, according to data provided by S&P Global Market Intelligence.