Hundreds of millions of dollars in Bitcoin, per the US Treasury, moved through Iranian exchange BitBank to the Islamic Revolutionary Guard Corps. BitBank processed payments received through Iran's Strait of Hormuz maritime scheme, a program Treasury calls Hormuz Safe, and helped transfer those funds to the IRGC. The action targets the exchange for its role at the center of that payment chain.
The IRGC, a US-designated foreign terrorist organization, received the Bitcoin that Hormuz Safe's maritime operations produced. BitBank sat between the scheme and the Revolutionary Guard. It processed the incoming payments and moved them forward. Treasury's designation names the exchange for that transfer function.
For $BTC, this is a protocol story more than a market one. Hormuz Safe ran its payments through Bitcoin. The Strait of Hormuz carries a substantial share of global seaborne oil traffic, placing the scheme's maritime revenue in a high-stakes corridor. BitBank handled the transfer side, and the volume Treasury places on the flow, hundreds of millions of dollars, is the number the designation turns on.