Crypto exchange Coinbase offered a fiery response on Thursday to last month’s Wells notice from the SEC, telling the federal regulator that an enforcement action against the crypto exchange would pose “major programmatic risks” to the SEC that would “fail on the merits.”

“Coinbase does not list, clear, or effect trading in securities,” the company’s response said. The analysis SEC did staffers to justify an enforcement action “appears to rest on superficial and incorrect analogies to products and services offered by others,” Coinbase wrote in a blog post from chief legal officer Paul Grewal.

Separately, Grewal told CNBC, “At the time when we went public we had detailed discussions with the SEC about the very aspects of our business that are now — two years later — the subject of the Wells notice. Nothing has changed.”

The SEC indicated to Coinbase in a March wells notice that its spot trading, staking, custody and institutional trading businesses were at risk. The SEC’s warning to Coinbase noted that the regulator would allege Coinbase was offering and selling unregistered securities, in violation of federal law. The SEC has used unregistered offering and sale violations to force other crypto exchanges to close services in the U.S., including the crypto exchange Kraken’s staking-as-a-service product.

If the SEC succeeded, it could force Coinbase to close down those units. To date, the SEC has never approved a crypto-asset entity as an national securities exchange, despite an extensive dialogue with Coinbase over the years.

Executives at the crypto firm have signaled for months that the Coinbase is ready to grapple with the SEC in an existential case not just for Coinbase but the future of the crypto industry in the U.S. at large.

Coinbase’s noted that the company’s years-long efforts to cooperate with SEC securities staff produced no concerns from SEC staffers until recently. Coinbase also noted that the SEC could have denied the company permission to go public in 2021, when it reviewed Coinbase’s S-1 filing.

Perhaps most consequentially for the rest of the U.S. crypto industry, Coinbase also argues that proposed charges rely on “flawed and untested” theories involving investment contracts, spot markets, and custody services.

Securities lawyers rely on something known as the Howey test, from a Supreme Court case where the SEC sued an Florida orange grove operator for a leaseback and profit-sharing arrangement involving the sale of oranges.

The four elements required to determine whether transactions constitute investment contracts: an investment, in common enterprise, and reasonable expectation of profit, from derived from the work of others.

Coinbase is a secondary market, meaning that investors buy and sell securities that they already own rather than purchasing them directly from an issuer. The Nasdaq and the NYSE are also secondary markets for U.S. equities. Courts have already been reluctant to extend “Howey’s reach to include the secondary trading of assets where no issuer is involved,” Coinbase’s response noted.

Coinbase also issued a point-by-point repudiation of Howey’s applicability to the exchange’s staking service. “Coinbase’s retail staking services fail all four prongs of the Howey test,” Coinbase’s response said.

Coinbase is represented by Sullivan & Cromwell.

“The SEC generally does not acknowledge the existence or non-existence of any investigation unless or until charges are filed,” a spokesperson for the SEC told CNBC.

“Coinbase has never wanted to litigate with the Commission. The Commission should not want to litigate either,” Coinbase wrote in its response. “Litigation will put the Commission’s own actions on trial,” Coinbase said, and “erode public trust cultivated over decades.