Kiss bassist Gene Simmons tweeted in February that he had bought $300,000 of the Cardano blockchain’s ADA currency, writing it was “one I believe in.”

The conviction has paid off for the rocker, with ADA’s price more than doubling since then. Based on back-of-the-envelope math, the token hoard would be worth more than $700,000 now.

ADA is one of 14 cryptocurrencies Simmons owns, he said Sunday in an interview on the Altcoin Daily YouTube channel.

“I like [c]ardano, although it’s an idiot name,” Simmons said. “Get rid of that thing. Just call it ADA. Call it by the trading name.”

Through a spokeswoman, Simmons, 72, declined to comment when contacted by CoinDesk.

In the YouTube interview, Simmons said he also owns bitcoin, ether (the native cryptocurrency of the Ethereum blockchain) and litecoin, among others.

He said he bought bitcoin when the price was around $10,000. Lately it’s trading just above $57,000.

“All my cryptos have done very well,” Simmons said.

The musician once known by his stage persona “The Demon” said he bought 0.2% of two cryptocurrencies that he thinks will go up tenfold. He declined to name them because if he did the prices would probably pump and “you’re going to have short-sellers.”

“I want the rise to be natural,” Simmons said.

He said he’s a “medium fan” of Charles Hoskinson, the lead developer of the Cardano blockchain.

“You live and die by the people who steer the company,” Simmons said.

Read more: Kiss’ Gene Simmons Buys $300,000 Worth of Cardano

He said BTC and ETH are the two biggest cryptocurrencies in his portfolio on a percentage basis.

And while he sold dogecoin (DOGE) earlier this year after Tesla CEO Elon Musk tweeted about it, he said he plans to hold his remaining cryptocurrencies for at least a decade.

“Do your own research,” Simmons said. “In the interest of full disclosure, nothing I’m saying means anything. Please ignore me. I’m not giving anybody advice.”