Tesla stock was—very—weak again Tuesday as investors digested early-year sales data, trying to determine whether a drop was due to random fluctuations or a more serious problem, such as whether CEO Elon Musk’s political activities are turning off customers.

Musk’s net worth fell almost 4% as of midday Tuesday, dropping to almost exactly $100 billion below his all-time high of $464 billion.

Tesla's stock tumbled 8% on Tuesday, pushing its market value below $1 trillion for the first time since November after data showed the electric car maker's sales slumped in Europe in January.