The Securities Exchange Commission (SEC) dropped a three-year investigation into blockchain software developer Hiro Systems (formerly Blockstack), which raised $70 million through token sales between 2017 and 2019, according to a filing on Friday. "Based on the information we have at this time, we do not intend to recommend that the commission take enforcement action against Hiro Systems PBC (formerly Blockstack PBC)," the Securities Exchange Commission's enforcement division said in a letter to Hiro attached to Friday's filing. The letter contained a set warning that such a notice "must not be construed as indicating that the party has been exonerated or that a staff investigation may not ultimately result in any action". Hiro provides tools for developers to build applications on Stacks, a Layer2 blockchain that complements Bitcoin. Stacks is the brainchild of crypto industry veteran Muneeb Ali, now CEO of Trust Machines, another builder of the ecosystem, and a member of Hiro's board.