(Reuters) -Tax software company Avalara disclosed on Monday it had confidentially filed for a U.S. initial public offering, as investor optimism for new listings grows.

U.S. IPO activity, sluggish at the start of the year, is gaining momentum following robust investor demand for new offerings.

Avalara went public in June 2018 and was taken private in 2022, when it was acquired by private equity firm Vista Equity Partners in a deal that valued the company at $8.4 billion, including debt.

Founded in 2004, Avalara runs a cloud-based software platform that helps companies with tax compliance.

The terms of the offering were not disclosed.