(Reuters) - Acorns Grow Inc said on Thursday it was going public through a merger with blank-check company Pioneer Merger Corp in a deal valuing the savings and investing app at about $2.2 billion. The merged entity will receive cash proceeds of over $450 million from the deal, which includes a private placement at $10 per share from investors such as Declaration Partners, Greycroft, TPG and BlackRock Inc. Launched in late 2014, Acorns helps users invest in stocks and bonds and operates on a subscription-based model. It has four million subscribers in the United States. The Irvine, California-based company counts digital payments giant PayPal, BlackRock and Comcast Corp among its investors. It also has a partnership with Comcast-owned CNBC to produce content aimed at financial literacy. Shares of Pioneer Merger were up nearly 3.6% on Thursday. The special-purpose acquisition company (SPAC) raised about $403 million in an initial public offering earlier this year. SPACs are shell companies that raise funds via a listing to acquire a private company to take it public, allowing such targets to sidestep a traditional IPO. The merger comes at a time of relative lull in the blank-check dealmaking space as concerns rise that SPACs have taken many companies, often loss-making or even those without revenue, public at high valuations. Increased regulatory scrutiny has also played a role in slowing what has been Wall Street’s biggest gold rush in recent years, with the U.S. Securities and Exchange Commission opening up an inquiry into the frenzy. Acorns said it would operate as Acorn Holdings Inc and trade on the Nasdaq under the symbol “OAKS” after the deal closes, which is expected to happen in the second half of 2021. Our Standards: The Thomson Reuters Trust Principles.