Miamisburg, Ohio maker of data-center power, cooling and white-space equipment, founded in 2017 by Michael and Shawn Rubiera. Its Nasdaq IPO (ticker ACCV) would raise up to $720 million gross, of which at most $207 million goes to the company itself. First-half revenue nearly tripled year over year to $437.5 million, but two customers provided 61% of last year's direct revenue and Olympus Partners keeps about 85% of the votes after listing.