Tesla CEO Elon Musk offloaded a combined $6.9 billion worth of shares in the electric car company this week, taking advantage of a meteoric rally that vaulted the firm’s value to over $1 trillion. The billionaire sold 1.2 million shares held by his trust for more than $1.2 billion on Friday, the latest in a flurry of his stock transactions, according to a U.S. securities filing released later in the day. The world’s richest person and Tesla’s top shareholder last Saturday wrote on Twitter that he would sell 10 percent of his shares if users of the social media platform approved the move. The 10 percent would be about 17 million shares at the time of his tweet. He has sold 6.36 million shares this week—around 37 percent of 17 million. He now needs to offload about 10 million more shares to fulfill his pledge to sell 10 percent of …