The offering was oversubscribed multiple times at the bottom of the proposed valuation range of 18.50 to 22.50 euros per share, in a sign that markets may be cautiously opening up to new entrants.
A meaningful portion of orders came from hedge funds in the run-up to the listing, a source close to the matter said before books closed on Tuesday.
The deal had piqued the interest of a significant number of investors, with roughly 750 meetings set up to market the IPO, the source added.
Underwriters for the deal may use an "over-allotment" option to issue additional shares, giving the company a free-float of 17.3%.
IONOS parent United Internet and minority
shareholder Warburg Pincus stand to rake in as much as 447
million euros from the float.
(Reporting by Pablo Mayo Cerqueiro, editing by Rachel More)