It was a stellar 2018 for developer brothers Arthur and Will Zeckendorf.

A penthouse at 520 Park Ave. quietly closed at the end of December for $67.92 million.

That makes it the second-priciest sale of the year.

The buyer is PH 56 Holdings LLC.

The top sale of 2018 was also at 520 Park Ave. — a penthouse that vacuum mogul Sir James Dyson sucked up for $73.8 million, as Gimme Shelter reported.

That follows in the footsteps of billionaire Frank Fertitta, former co-owner of the Ultimate Fighting Championship, who bought a $70 million penthouse there in August 2017.