Cipher Mining (CIFR 0.61%) closed at $11.64, down 17.7%. Trading volume surged to about 153 million shares, roughly 4.1 times its three-month average.
Indexes finished lower. The S&P 500 (^GSPC 0.53%) fell 0.5% to 6,604.72, and the Nasdaq Composite (^IXIC 0.52%) declined 0.5% to 22,384.70, as losses in technology stocks pressured the market.
Among Bitcoin mining peers, Riot Platforms (RIOT 2.69%) dropped 7% to $16.74, and Hut 8 Corp (HUT -0.70%) slid 7.9% to $34.88. The declines reflected weakness in Bitcoin (BTC 2.27%), which fell 3.4% to $109,534.50, pulling down crypto-related equities across the sector.
Cipher's loss came even after it announced a 10-year artificial intelligence (AI) hosting agreement with Fluidstack, valued at about $3 billion, with extensions that could bring the total near $7 billion. Alphabet (GOOGL 0.82%) (GOOG 0.86%) will guarantee $1.4 billion of lease obligations under the deal and receive warrants representing roughly 5.4% equity in Cipher. While the agreement highlights Cipher's expansion into high-performance computing, today's trading showed the stock's continued sensitivity to swings in Bitcoin.
Market data sourced from Google Finance and Yahoo! Finance on Thursday, Sept. 25, 2025.
