Stacks uses the Bitcoin blockchain as its base layer. As a [Proof of Work (PoW)](https://coinmarketcap.com/alexandria/article/proof-of-work-vs-proof-of-stake)-based blockchain, Bitcoin uses the combined efforts of thousands of miners and nodes to protect the network against [attacks](https://coinmarketcap.com/alexandria/glossary/51-attack) by making it computationally and economically unfeasible to subvert the network. On top of this, Stacks introduces its own consensus model, known as proof-of-transfer (PoX), which is a novel mining mechanism that sees users transfer the base currency (BTC) to mine STX — effectively bootstrapping the security of the Stacks blockchain using BTC.

The Stacks cryptocurrency has a predefined future supply that reaches approx 1,818M STX by year 2050. The Stacks ecosystem is a collection of independent entities, developers, and community members working to build a user-owned internet on Bitcoin. No entity in the space holds >10% of the circulating STX supply. Even the early investors/entities generally hold less than 5%. These stats are self-reported and from on-chain data and naturally update over time.

* As a Bitcoin layer for smart contracts, Stacks has the following innovations that make it unique: * In the upcoming release of Stacks, Stacks will be secured by the entire hash power of Bitcoin, giving it Bitcoin finality. * Stacks will soon have a novel backed Bitcoin that is 1:1 backed with BTC on Bitcoin L1, and can be moved in and out of the Stacks layer in a decentralized way. * The new 1:1 Bitcoin backed asset called sBTC enables Stacks smart contracts to write to Bitcoin. * Stacks powers atomic BTC swaps and assets owned by BTC addresses. * Stacks uses the Clarity programming language for safe, decidable contracts. * Stacks has knowledge of the full Bitcoin state, thanks to Proof of Transfer and Clarity, enabling it to read from Bitcoin at any time. * Lastly, Stacks is a scalable layer that enables fast transactions that settle on Bitcoin.

The project started in 2017 when Muneeb finished his PhD ([his thesis laid out the foundations for the Stacks layer for Bitcoin](https://www.google.com/url?q=https://www.cs.princeton.edu/research/techreps/TR-003-17&sa=D&source=docs&ust=1678030902432250&usg=AOvVaw3GPZe_ECpyHTAy5YfG5GDL)), released the original whitepaper, and raised $50M. Before this, the early team built protocols and apps on Bitcoin L1 before they began working on Stacks in 2017. Some early visions of the project are represented in this TEDx talk. In 2019 there was the first-ever SEC qualified token offering ([see WSJ article](https://www.wsj.com/articles/sec-clears-blockstack-to-hold-first-regulated-token-offering-11562794848)) for the general public, including the US. The [full offering material](https://www.sec.gov/Archives/edgar/data/1719379/000110465919020748/a18-15736_1partiiandiii.html) disclosed everything and anything about the project/company/people. 2018-2020 the team was heads down building out the Stacks infrastructure— it's a programming layer for Bitcoin (it works like a blockchain with cross-chain consensus with Bitcoin) and Clarity lang, a safe language. Some technical re[sources are here](https://https://github.com/stacks-network/stacks).

Stacks is a Bitcoin Layer for smart contracts; it enables smart contracts and decentralized applications to use Bitcoin as an asset and settle transactions on the Bitcoin blockchain. Bitcoin is the largest, most valuable, and most durable decentralized asset. The Stacks layer unlocks $500B in BTC capital using the Bitcoin L1 as settlement for decentralized applications. Stacks has knowledge of the full Bitcoin state, thanks to its Proof of Transfer consensus and Clarity language, enabling it to read from Bitcoin at any time. All transactions on the Stacks layer are automatically hashed and settled on the Bitcoin L1. Stacks blocks are secured by 100% Bitcoin hashpower. In order to re-order Stacks blocks/transactions, an attacker would have to reorg Bitcoin.