Jack Mallers (잭 말러스) has stepped down as chief executive of Twenty One Capital to focus on bitcoin payments firm Strike. He said it had become clear to him what he needed to build next, prompting his resignation.

Mallers is the founder and CEO of Strike and has led payment and remittance services using the Bitcoin Lightning Network. He became known in the industry after being involved in El Salvador's adoption of bitcoin as legal tender. He later co-founded bitcoin treasury firm Twenty One Capital and served as its first CEO.

CryptoSlate, a blockchain news outlet, reported on Monday that Mallers' resignation also halted a merger plan being reviewed by Twenty One and Strike.

Rafael Zagury will succeed him. Zagury, a board member, will be tasked with building a cash-generating business based on large bitcoin treasury assets, drawing on his experience in capital markets and bitcoin infrastructure. Tether confirmed the succession and said the two companies were carrying out an orderly transition.

The change means Twenty One must drop its earlier expansion plans and redesign its operating model. In April, Twenty One announced an operating plan centered on the potential acquisition of Strike and an Electron acquisition tied to a bitcoin mining and energy infrastructure business associated with Zagury. But in a first-quarter filing submitted in May, the company said neither deal had any binding agreement or contract, and no board approval had been granted.

The issue is that Twenty One remains a large bitcoin holder. As of March 31, it held 43,514 BTC with a fair value of about $2.95 billion and had about $114.1 million in cash.

In the same filing, Twenty One said it recorded a fair-value loss of about $847.8 million on its bitcoin position during the quarter. It also said it pledged about 16,116 BTC as collateral for convertible bonds. The loss does not mean the same amount of cash outflow, but it clearly showed a structure in which bitcoin price moves are directly reflected in results.

Twenty One has said it would expand profit-making businesses using its holdings, including financial services, lending and capital market products, while increasing its bitcoin holdings per share. Zagury also said Twenty One should be judged by how much cash flow it generates and how prudently it allocates capital. Paolo Ardoino, Tether's CEO, also stressed Zagury's experience in building cash-flow businesses and his disciplined execution.

Zagury's remarks show that the sustainability of the financial structure has become more important than the scale of bitcoin holdings itself. Large bitcoin-holding companies have recently been forced to balance debt repayment, collateral requirements, dividends and share buybacks against additional purchases. Concerns are also growing that if funding conditions worsen, bitcoin could shift from being a simple reserve asset to a source of corporate liquidity.

That pressure is spreading to funding tools. Preferred shares linked to bitcoin treasury strategies traded below par during a selloff in June. Dividends were maintained and the market remained open, but investors are reassessing whether such structures can withstand long-term volatility.

Ultimately, Twenty One's new task is clear. It is easy to expand treasury assets when capital is easy to raise and bitcoin prices are rising. But after Strike chose an independent path, Twenty One now faces the need to prove it can support broader businesses using only its own bitcoin balance sheet.

I've decided to step down as CEO of Twenty One. This wasn't an easy decision, but it was the right one. This experience brought tremendous clarity about who I am and what I want to build. My life's work remains Bitcoin. My Bitcoin company is @Strike. The work continues. pic.twitter.com/L70YFYPt11