Cboe Global Markets once again has prodded the US Securities and Exchange Commission to approve cryptocurrency based exchange-traded products.

In a letter addressed to Dalia Blass, director of the Division of Investment Management at the SEC and dated March 23, Chris Concannon, president and COO at Cboe Global Markets, laid out the exchange operator’s arguments for such approval.

“While cryptocurrency-related holdings do raise a number of unique issues, Cboe firmly believes that such holding to not require significant revision to the well-established frameworks for evaluation related to valuation, liquidity, custody, arbitrage, and manipulation,” wrote Concannon. “Rather, each Cryptocurrency Fund and underlying cryptocurrency-related holdings should be evaluated on a case-by-case basis in a manner very similar to previous funds and their underlying holdings.”

Concannon noted that as cryptocurrency markets grow and mature especially the spot and regulated derivatives markets, the easier it will be for those markets to fit within the existing regulatory framework.

He also recommended that the regulator approach cryptocurrency ETPs in the same holistic and historical way that the SEC approaches commodity-based ETPs.

The new ETPs would provide a more transparent and easily accessible vehicle for gaining exposure to the underly reference asset, according to Concannon.

“The market and infrastructure for the underlying reference asset and its associated derivatives do not give rise to significant concerns in any of the five overarching issues raised in the Staff Letter,” he added.

The letter represents the latest nudge that the Cboe Global Markets has given the regulator after first proposing a bitcoin-based ETP in July 2016.