• Shares of Rivian and Lucid Motors continued to fall Thursday as investors took profits.
• Rivian and Lucid both dropped about 17% during afternoon trading.
• The electric-vehicle makers have gained attention as investors seek out the next Tesla.

Shares of Rivian and Lucid Motors continued to fall Thursday as investors take profits and pull back from some of the EV hype driven by Rivian's monster market debut.

Both stocks dropped about 17% during afternoon trading. Rivian closed down 15.53% while Lucid closed down 10.47%.

The electric-vehicle makers have gained attention as investors seek out the next Tesla.

Rivian went public Nov. 10 in one of the biggest IPOs of the year. It quickly surpassed the market cap of legacy automakers such as Ford and General Motors but still trails Tesla, which recently passed a $1 trillion market cap. Shares continued to rocket until Wednesday when the stock closed down 15% as speculation in the name eased. Rivian has yet to establish a business model and said it expects up to $1 million in revenue in the third quarter.

Shares of Lucid jumped 23% on Tuesday after executives told investors that the company saw increased reservations for its vehicles and that it's still on track to build 20,000 Lucid Air sedans in 2022. Lucid began commercial production of its Air sedan in September. Lucid is up more than 360% year to date.

CNBC's Jim Cramer urged investors Wednesday to "remember the lessons" of the 1999 dot-com bubble and to take profits off the table.

"If you own Lucid or Rivian and you've made a ton of money, you have my blessing — right here, right now, tomorrow morning — to literally take half off the table ... and you can let the rest ride," he said.