Sanders, 80, called on the nation's "extremely wealthy" to pay up more cash in a tweet Saturday, attracting the attention of Musk, who last week sold more than $5billion of his Tesla stake.
He did so after posting a Twitter poll that led him toward selling $25billion in stock to fund President Joe Biden's offered billionaire tax. Musk, responding to Sanders' needs, indicated he wouldn't draw the line there.
"I keep forgetting that you're still alive," Musk, the world's richest man, tweeted at the senator.
"Want me to sell more stock, Bernie? Just say the word …." Meanwhile, British investor Jeremy Grantham sounds the alarm on the stock market, suggesting that Tesla's stock is in a bubble and expected to fall.
FROM CONTROVERSY TO COMPASSION: DANIEL SNYDER'S JAW-DROPPING GIFT LEAVES NATION IN AWE
"I'm very grateful for Tesla as a dedicated green, that they have pioneered EVs," Grantham, of the firm Grantham, Mayo & van Otterloo, told Bloomberg on Friday. "But now in phase two, every great automobile company are all gearing up to go electric.
WATCH: RFK JR. WILL REVERSE 80 YEARS OF FARM POLICY
"And that owes a lot to Tesla, but now in phase two they're going to have to have some serious competition. And to live up to the expectations of the price will be impossible."
Musk pawned off another $687 million worth of Tesla shares on November 11 after offloading $5 billion of his stake in the company in two separate transactions earlier this week, following the CEO's promise to sell $25 billion worth of the stock.
JAMES CARVILLE'S CONTROVERSIAL CRITIQUE: IS WOKE CULTURE KILLING DEMOCRATIC SUPPORT?
The series of sales came less than a week after Musk's much-publicized Twitter poll where he asked followers if he should sell his $250 billion stakes in the electric-car maker to pay for the billionaire tax.
In a November 6 post, Tesla's top shareholder slammed the controversial new tax plan proposed by the president's administration, saying that he does not earn a paycheck from the company and his only source of income stocks and that the only way for him to pay taxes would be to sell some of his stakes.
INTRUDER SLIPS PAST TSA, BOARDS DELTA PLANE, IN EPIC SECURITY FAILURE
Musk, 50, who founded the car company in 2003, then declared to his 63.1 million followers that he would sell 10 percent of his shares - which would equate to roughly $25 billion - if they approved the move.
"Much is made lately of unrealized gains being a means of tax avoidance, so I propose selling 10% of my Tesla stock," Musk, 50, wrote in the November 6 post.
The exec then pressed his 63.1 million followers: "Do you support this?"
They did - with more than 2 million of the 3.5 million social media users surveyed voting that he should, encouraging the CEO's massive sell-off.