Secure smart contracts and apps for Bitcoin. The Stacks 2.0 blockchain extends the design of Bitcoin to enable secure apps and predictable Clarity smart contracts without modifying Bitcoin itself, opening innovation on the network for the first time. The Stacks cryptocurrency(STX) is used as fuel for networking activity and contract execution and can be locked by STX holders via ‘Stacking’ to earn Bitcoin(BTC) rewards for supporting blockchain consensus. Stacks cryptocurrency was distributed to the general public through the first-ever SEC qualified token offering in US history. Stacks is supported by the Stacks ecosystem, a collection of independent entities, developers, hodlers, and community members working to build a user-owned internet on Bitcoin.