Bitcoin onchain activity surges to yearly high as Coldcard attack unfolds

Bitcoin onchain activity has reached its highest level of 2026 as researchers have linked the surge to the ongoing Coldcard wallet exploit, warning that similar spikes have historically coincided with local market turning points. Summary Bitcoin onchain activity has reached its highest level of 2026 as the Coldcard wallet exploit continues to unfold. K33 said similar spikes in Bitcoin activity have historically appeared around local market tops and bottoms. Galaxy Research has confirmed the theft of 1,596 BTC from about 7,300 addresses, with losses potentially rising to around 2,055 BTC. The Coldcard breach has prompted some users to move funds to centralized exchanges while raising new questions about hardware wallet security. K33 Research said nearly 890,000 BTC has moved onchain over the past seven days, the highest seven-day active supply recorded this year, even as Bitcoin has continued trading within one of its tightest price ranges in recent years. The research note arrives as investigators continue expanding the scope of the Coldcard hardware wallet breach. Galaxy Research said on Tuesday that at least 15 different attackers have now exploited the vulnerability, while its l...