There's more going on than just a very wealthy guy talking about business, finance and investing but for now we'll just take this as presented.
From Bloomberg via Yahoo Finance, December 24:
Billionaire Elon Musk is warning against something he himself has done — borrowing against the value of securities one owns — because of the risk of “mass panic” in the stock market.
“I would really advise people not to have margin debt in a volatile stock market and you know, from a cash standpoint, keep powder dry,” Musk said in the All-In podcast released Friday. “You can get some pretty extreme things happening in a down market.”
The Tesla Inc. chief executive officer put up billions of his own money when he purchased Twitter Inc. for $44 billion earlier this year and saddled the company with $13 billion of debt. Bloomberg News has reported that Musk’s bankers are considering replacing some of the high-interest debt he layered on Twitter with new margin loans backed by Tesla stock that he’d be personally responsible for re-paying....
....MUCH MORE
