'The Big Short' investor Michael Burry spars with Elon Musk over Rivian's 'true test' in his 2nd Twitter spat with the Tesla CEO this week

• The Big Short's Michael Burry sparred with Elon Musk on Twitter over what Rivian's "true test" would be.
• EV-maker Rivian, a Tesla competitor, had a blockbuster IPO this week.

Michael Burry hit back at Tesla's Elon Musk on Twitter Friday for the second time this week, sparring this round over electric-truck maker Rivian.

In Rivian's public debut this week, the company scored a valuation higher than that of legacy automakers like Ford and General Motors. Musk commented on his competitor's blockbuster IPO by saying the "true test" is whether Rivian can achieve high production and breakeven cash flow.

But Burry tweeted back at him: "No, @elonmusk, the true test is achieving that without massive government and electricity subsidies on the backs of taxpayers who don't own your cars." Burry later deleted the tweet, something he's known for doing.

That's not the first time this week the Scion Asset Management boss and star of Michael Lewis's "The Big Short" has mentioned Musk in a tweet.

Musk, who said he would donate $6 billion if the United Nations could prove that amount would solve world hunger, tweeted a poll on November 6 asking if he should sell 10% of his Tesla stake because "much is made lately of unrealized gains being a means of tax avoidance." The resounding answer was yes, and he's since offloaded about $5.7 billion worth of Tesla shares.

On Monday, Burry suggested the reason the Tesla CEO was really interested in selling $6 billion worth of shares in his company - and it had nothing to do with world hunger or taxes. Burry linked to an SEC filing that showed Musk had pledged about 88 million shares, or 36% of his total stake, as collateral for personal loans as of June 30.

In another tweet on Wednesday, Burry said Tesla's stock could plunge 90% - like Amazon did when the 90s dot-com bubble burst. "$AMZN fell 95% 2 decades ago, changed its whole biz, and thrived much later," he wrote in a now-deleted tweet.