Bitcoin savings app Bitstack completes $15 million Series A funding, led by 13books Capital

French Bitcoin savings app Bitstack announced the completion of a $15 million Series A funding round, led by 13books Capital, with follow-on investments from existing shareholders including YC, Serena, and Plug and Play.

The new funds will be used for expansion in Europe and product upgrades, including the launch of a VISA debit card with Bitcoin cashback (Stackback) in January 2026. Bitstack claims its goal is to become "the leading Bitcoin savings platform in Europe."