Five companies this morning announced plans to go public via reverse mergers with SPACs, at an aggregate market value of more than $15 billion. And there might be even more by the time you read this.

The bottom line: SPAC merger activity hasn't peaked. If anything, it's just getting started.

Driving the news:

• Alight, a Blackstone Group-backed benefits services provider, for $7.3 billion by a Bill Foley-led SPAC.
• The Hillman Group, a home improvement hardware maker owned by CCMP Capital, for $2.6 billion to a SPAC led by Tilman Fertitta and Rich Handler.
• Taboola, a VC-backed content recommendation company, for $2.6 billion by a Gilad Shany-led SPAC.
• Latch, a VC-backed smart lock startup, for $1.56 billion by a SPAC formed by Tishman Speyer Properties.
• Sunlight Financial, a private equity-backed residential solar financing platform, for $1.3 billion by a SPAC formed by Apollo Global Management.

Coming attractions: More SPAC merger announcements are anticipated shortly, including deals in the EV, ed-tech and aerospace sectors.

What's happening: A lot of this can just be chalked up to supply and demand, the predictable consequence of surging private funding flows and a record amount of new SPAC issuance.

• I'm also hearing an argument that private market investors, and their portfolio companies, are increasingly worried about a valuation bubble. SPACs provide a quicker route to listing than do traditional IPOs, thus lowering the risk of finding themselves on the wrong side of a pop or deflation.
• The counterargument is that SPACs aren't quite as fast as they're sometimes made out to be. In the case of Alight, for example, a source tells me that Blackstone began talking to Bill Foley last August, with serious negotiations beginning a couple of months ago. Today's announced deal does have committed PIPE financing, but still requires a SPAC shareholder vote and isn't slated to close until sometime in Q2.