Bitcoin billionaire Author Hayes warned investors on Wednesday to remove their Zcash holdings from exchanges amid increased volatility for the privacy coin. 

Writing on X Wednesday, the former BitMEX boss urged his nearly 766,000 followers to move their Zcash to self-custodial wallets. 

“If you hold $ZEC on a CEX, withdraw it to a self-custodial wallet and shield it,” he wrote, referring to centralized exchanges like Coinbase and Binance. 

Zcash, the 24th largest digital coin by market value, was trading above $537, up more than 10% over the past 24 hours, according to crypto markets data provider CoinGecko. But the token plunged as low as $430 earlier Wednesday and is about 30% off its high of the previous week, and far removed from its record of $3,192, set in 2016. 

Hayes, whom U.S. President Donald Trump pardoned earlier this year, also tweeted about Zcash on Tuesday, speculating on the digital coin’s price action and whether he would buy more. 

The billionaire’s Wednesday advice follows that of crypto industry heavyweights who argue that holding funds on exchanges is dangerous because centralized platforms are vulnerable to hackers. Hayes, a strong industry advocate, has been outspoken about a range of digital asset-related topics, including bold predictions for Bitcoin and Ethereum, the two largest cryptocurrencies by market capitalization. 

As a privacy coin, Zcash enables users to send and receive money in private by encrypting transaction information using zero-knowledge proofs—a cryptographic method that proves something is known without revealing the known information directly.

In the past, many market observers have recommended strongly against keeping privacy coins on centralized exchanges because so-called CEXs record customer details, including name, address, and credit card information on their books. Privacy coins aim to prevent tracking who is sending and receiving the crypto. 

Zcash rallied last month amid concerns about the government’s ability to track Bitcoin users due to BTC’s transparent nature. 

Entrepreneur and AngelList founder Naval Ravikant wrote that while “Bitcoin is insurance against fiat,” Zcash is insurance against Bitcoin.”