New Delhi, July 12 -- WASHINGTON - When the United States launched its third round of airstrikes against Iran this week, most major financial markets were closed. Bitcoin was not.

The world's largest cryptocurrency held near $63,800 on Saturday, down just 0.3 percent over 24 hours, as US Central Command confirmed strikes on Iranian military infrastructure following Tehran's declaration that the Strait of Hormuz was closed indefinitely. Ethereum settled near $1,800, also up 2 percent on the week. XRP traded at $1.09. The digital asset class, in aggregate, absorbed the weekend's geopolitical shocks with a composure that will be tested when oil, equities, and bond markets reopen Monday.

The immediate cause of the US strikes was an attack b...