Feb 18 (Reuters) - Tesla Inc CEO Elon Musk onThursday said that owning bitcoin was only a little better thanholding conventional cash, but that the slight difference madeit a better asset to hold.

"However, when fiat currency has negative real interest,only a fool wouldn't look elsewhere," Musk said in a tweet."Bitcoin is almost as bs as fiat money. The key word is'almost'."

He also defended Tesla's action to invest in bitcoin, sayingthat the difference with cash made it "adventurous enough" forthe S&P 500 company to hold the cryptocurrency.

Tesla's $1.5 billion bitcoin purchase set the cryptocurrencysoaring toward this week's record peak above $50,000 whileMusk's recent promotion of dogecoin on Twitter also lifted theprice of that cryptocurrency.

Bitcoin was steady just below a record peak of$51,284 on Friday.(Reporting by Aishwarya Nair and Shubham Kalia in Bengaluru;Editing by Sam Holmes)