Tesla Inc. (Nasdaq: TSLA US) CEO Elon Musk, unloaded $5 billion of stock in the electric car-maker, shortly after holding a poll on Twitter over whether he should sell 10% of his massive stake in the company. The world’s richest person so far has disposed of more than 4.5 million shares this week, according to regulatory filings Wednesday. Those were his first sales in more than five years. On Monday, Musk offloaded about $1.1 billion worth of stock to pay income taxes on equity options that he also exercised that day, two of the filings showed. Those transactions were made based on a pre-arranged trading plan adopted in mid-September. Tesla shares are 51,3% up this year.