Cryptocurrency options exchange Deribit is still talking to Kraken for a potential acquisition, contrary to reports that the U.S. exchange had walked away from a potential deal to buy Deribit, a person familiar with the matter said.

Recent reports also confirmed the crypto options platform was working with FT Partners to assess takeover bids, but Deribit CEO Luuk Strijers ruled out a takeover situation. The firm could be valued at $4 billion- $5 billion or even more, according to Bloomberg.

A second source said listed U.S. exchange Coinbase (COIN) has also been kicking the tires of Deribit.

Deribit is an appealing takeover target because it’s the overwhelming market-leading exchange for digital asset options trading, which Kraken would be looking to add to its trading offering, Strijers had said in an earlier report.

Kraken and Deribit declined to comment. Coinbase did not respond to requests for comment by press time