Elon Musk has sold at least another $3.95 billion worth of shares in his electric car company Tesla after closing his $44 billion acquisition of Twitter.This year, he sold over $8 billion worth of stock in April and roughly $7 billion worth in August.In addition to pouring billions of his own capital into taking Twitter private, the Tesla CEO relied on partners, including equity investors Binance, Ron Baron's BAMCO, Andreessen Horowitz, Twitter's former CEO Jack Dorsey and Prince Alwaleed bin Talal bin Abdulaziz of Saudi Arabia, to finance the deal, or to roll their existing shares into his holding company for Twitter.As NBC News previously reported, Sen. Chris Murphy (D-Conn) has called for an investigation into the national security implications of Saudi Arabia's stake in Twitter following Musk's take-private deal.On Aug. 9, Musk told fans he was done selling Tesla shares to fund a possible Twitter acquisition."