Bitcoin surpassed $12,000 (about ¥1.3 million) on Wednesday for the first time amid speculation that the widespread use of futures will help lead to digital currencies being viewed as a legitimate asset class for mainstream investors.

The largest cryptocurrency by market value has soared from less than $1,000 at the start of the year as optimism climbs for the distributed ledger technology known as blockchain that is at the heart of bitcoin. The price surge has been accompanied by a growing chorus of warnings that the speculative frenzy is an asset bubble poised to burst.

Cboe Global Markets Inc. has said it will start trading bitcoin futures on Dec. 10, while CME Group Inc.'s contracts are set to debut on Dec. 18. Nasdaq Inc. is planning to offer futures in 2018, according to a person familiar with the matter. Cantor Fitzgerald LP's Cantor Exchange is creating a bitcoin derivative, and startup LedgerX already offers options.

Echoing the rivals that plan to list contracts tracking the cryptocurrency, one of Japan's leading financial exchanges is starting preparations to launch bitcoin derivatives.

Tokyo Financial Exchange Inc., which counts JPMorgan Chase & Co. and Barclays Bank PLC among its trading participants, plans to create a working group to study cryptocurrencies in January, Chief Executive Officer Shozo Ohta told reporters late last week. The listing would require changes to the nation's securities law, he said. In Japan, the start of a working group is typically the first step toward drafting legislation.