Elon Musk boosts his pledge to swap a 10% stake in Tesla.

By Hamza Hayat

Elon Musk made further development towards his pledge to sell 10% of his stake in Tesla Inc, and it may have cost the automaker its $1 trillion valuations.

According to regulatory filings, the world's wealthiest person divested another 934,091 shares on Monday for about $906.5 million to cover taxes on the exercise of 2.1 million more options.

It has now sold a total of $12.7 billion worth of shares over five weeks.

The latest transactions coincided with Tesla closing below $1 trillion in market cap for the first time since Oct 22.

The shares continued to slide on Tuesday, falling 2.3% to $943.81 as of 9:43 a.m. in New York.

Musk's selling had dragged down shares of Tesla, which peaked just before he conducted a Twitter poll over the weekend on whether he should cut his stake.

You have now sold about 70% of the shares you would need to offload your 10% direct share ownership.

Before conducting the Twitter poll, Musk said in September that he would exercise a "huge block" of options in the fourth quarter.

It launched a trading plan that month that accounted for more than half of the stock sales that began in November.

He has now exercised a total of nearly 15 million options.

As is often the case, Musk has been busy on Twitter since his last stock sale. 

He announced that Space Exploration Technologies Corp would start trying to get carbon dioxide out of the atmosphere and turn it into rocket fuel. Tesla will start accepting Dogecoin for some merchandise.