Mercato is a very Italian tradition ( see: https://misshome.wordpress.com/2013/07/28/28-i-miss-mercato/ )
Starting from the end of november mercati, are full of stands of Christmas decorations, statuine del presepe (little statues for the presepe), agrifoglio (‘Christmas holly’) or vischio (‘mistetoe’).
But there are mercati totally dedicated to Christmas products: i mercatini di Natale
Mercatini di Natale are particularly common in Northern Italy; Bolzano is probably the most famous town for mercatini
In Alto Adige area mercatini last for the whole Avvento (‘Advent’), they sell decorations for the house, the Christmas tree and presepe,
often during the mercatini, there is the sfilata (‘parade’) of San Nicola and his “staff”, namely the Krampush, devilish creatures that accompany him.