When we launched, 25 million WSP was pre-mined (hence the PoW phase) and distributed during a swap we offered to our community. As soon as the 25 million had been mined, PoS was enabled and our network went live.

In order to fully read what happened I advise you to read our blog post, posted the day after the swap, back in December 2017: https://medium.com/wispr-blockchain-technology-revolutionizing/an-update-from-the-team-2f94e5a5398f