Tesla CEO Elon Musk sold more than $6.9 billion worth of shares in the electric carmaker this week, according to regulatory filings released Friday.

The 50-year-old South African billionaire sold more than 5.1 million Tesla shares, of which about 4.2 million were held in a trust. 

This is one of the largest sales that have been recorded in a short period of time without being a mandatory sale or as part of a transfer of ownership.

It greatly affected the price of one Tesla share, which lost 15.4% of its value over the week.

Tesla last month became the latest US tech giant to hit $1 trillion in market value.

Musk's selloff came days after he created a Twitter poll, in which millions voted, asking whether he should sell 10 percent of his huge stake in the electric carmaker.

On Saturday, Musk tweeted: 

Much is made lately of unrealized gains being a means of tax avoidance, so I propose selling 10% of my Tesla stock.

Do you support this?

— Elon Musk (@elonmusk) November 6, 2021

In the poll, almost 58 percent of the 3.5 million votes cast were in favor of him proceeding with the sale.

Tesla shares had plummeted at the Wall Street opening on Monday and have fallen further since.

The stock Musk disposed of this week was sold at a significantly lower share price than if he had sold before his tweet.

Regulatory filings showed the tech entrepreneur had initiated the sale of at least some of these shares before his Twitter poll.

According to the latest filings with the Securities and Exchange Commission, Musk still holds about 167 million Tesla shares.

His tweets followed a proposal by US Congressional Democrats to tax the super-wealthy more heavily by targeting stocks, which are usually only taxed when sold.

Musk is the world's richest person, worth $294 billion according to the Bloomberg Billionaires Index.