Key Points Sigma Lithium stock slumped on Thursday, and it's failing to recover. The company received a downgrade from Canaccord yesterday. After stopping operations at an asset in Brazil, Sigma Lithium is facing opposition in resuming activities. 10 stocks we like better than Sigma Lithium › Falling more than 14% yesterday from where it closed on Wednesday, Sigma Lithium (NASDAQ: SGML) seems likely to extend its downward trajectory to end the week. With shares of the lithium producer downgraded ...