Pelosi卖了10,000，又exercised 500 call options. 不太懂options，不知为啥？

Pelosi sold 10,000 shares of NVIDIA Corporation (NASDAQ:NVDA) common stock for $1 million to $5 million. She also exercised 500 call options on Nvidia worth between $500,001 to $1 million

她卖股份，说明看低后市。却为啥又买call呢？