Euro zone government bond yields saw a slight increase on the first trading day of the new year, influenced by anticipated large debt sales and geopolitical factors. Germany's 10-year Bund yield rose, continuing a trend from the previous year. While French yields also increased, Italian yields remained stable and UK gilt yields fell. Analysts anticipate continued upward pressure on borrowing costs due to record net supply from private investors, with Germany planning new bond issuances. Investor sentiment on future yields remains mixed, with focus on the effectiveness of German fiscal stimulus.