Stacks

STX is the token of Stacks, a network that adds smart contracts and apps to Bitcoin.

Stacks is a blockchain that adds smart contracts and apps to Bitcoin. It began as Blockstack, founded by Muneeb Ali and Ryan Shea in 2013, and was renamed Stacks in 2020. The current network, Stacks 2.0, launched on 14 January 2021. STX is its native coin: it pays transaction fees and is the reward that miners receive for producing blocks.

Stacks uses Proof of Transfer. Miners spend BTC to bid for the right to produce Stacks blocks and receive newly issued STX. The BTC they spend funds rewards for people who lock their STX, which is called stacking. Since the PoX-5 upgrade of July 2026, BTC holders can also lock BTC together with STX in six-month 'bonds'. Bonds are paid a target yield first, and the rest of the miner BTC goes 85% to STX stackers and 15% to a reserve.

About 1.87 billion STX existed on 27 September 2026, all of it unlocked. There is no fixed cap: PoX-5 set new issuance at 1,000 STX per Bitcoin block, and the project's own data projects about 2.32 billion STX by 2050. sBTC, a token backed 1:1 by BTC held by a group of signers, lets Bitcoin move into Stacks apps.

In 2019 Blockstack sold STX in one of the first two token offerings qualified by the US SEC under Regulation A, and treated STX as a security at the time. After Stacks 2.0 launched, the company said STX was no longer a security. Development is now spread across the Stacks Foundation, Hiro and other teams, and protocol changes go through public improvement proposals (SIPs) and holder votes.