Bitcoin Core's development activity saw a significant resurgence in 2025, with a 60% increase in developer mailing list activity, according to Casa's Chief Security Officer Jameson Lopp. The number of contributors to the Bitcoin Core codebase rose to 135, up from 112 in 2024, marking a recovery from a decline since 2018. Additionally, Bitcoin Core underwent its first public third-party security audit, conducted by Quarkslab and funded by Brink, which found no critical vulnerabilities. VanEck continued its support by allocating 5% of its spot Bitcoin ETF profits to Brink's development grants.