Shares of Bitcoin miner Iris Energy Ltd. climbed roughly 10% on 1 July, briefly topping their December peak after about 3.5 million shares changed hands in a five-minute span. Market participants also showed heightened interest in derivatives tied to the stock, with buying concentrated in July 25 $17 call options. Unusual activity spread to peer Cipher Mining Inc. Traders exchanged 18,000 January $15 call contracts in the company, contributing to what Citadel described as the fifth-largest quarter-over-quarter increase in options volume across U.S. equities. The most popular strikes for CIFR during the session were July and August $6 calls. Despite the surge in IREN and CIFR contracts, Citadel said neither ticker ranked among the 20 most-traded names by total option volume for the day, suggesting the moves were concentrated rather than broad-based. Core Scientific Inc. briefly turned positive alongside the rally in cryptocurrency-linked mining stocks.