Long-time Tesla executive and president Jerome Guillen, who left the company earlier this month, has sold an estimated $274 million worth of shares after exercising stock options since June 10, according to a filing with the US Securities and Exchange Commission (SEC). The filing, which was submitted to the SEC on June 15, said that Mr Guillen expected to sell 215,718 shares for $129m that day. He also offloaded 145,289 shares worth $89.6m on June 14, and 90,111 shares worth $55m on June 10. Mr Guillen, a former Mercedes engineer who was with Tesla since 2010, oversaw the company's entire vehicles business before being named president of the Tesla Heavy Trucking unit in March. He left the company on June 3. The departure of Mr Guillen, one of Tesla's top four leaders, including founder and chief executive Elon Musk, has sparked market concerns about the electric car maker's future vehicle programs, such as the Semi electric truck and new batteries called 4680 cells. Gordon Johnson, an analyst at GLJ Research, estimated that Mr Guillen has cut his exposure to Tesla from 1.3 million shares a week ago to about 150,000 as of Friday. “Should TSLA be on the verge of technological and autonomous breakthroughs and breakout 2Q21E deliveries/earnings, as well as EV domination, why has what many assumed was the second-most important person at the company [Jerome Guillen] sold $274m worth of TSLA stock," Mr Johnson said in a report. "It could raise some eyebrows for investors," Wedbush Securities analyst Daniel Ives said, adding that investors are going to watch closely to see if he sells more. Stock options give employees and executives the right to buy their company's stock at a specified price for a certain period of time. When share prices rise above the exercise price, they can buy the stocks at discounted prices. It was not immediately known how much Mr Guillen paid to exercise the options.