Statistical learnings from a failed 2024 santa rally

Intro Santa Claus Rally is a well-known narrative in the stock market, where it is claimed that investors often see positive returns during the final week of the year, from December 25th to January 2nd. But is it a real pattern or just a market myth ? It is also claimed that next years returns are positively correlated to the Santa rally. But is it a real pattern or just a market myth ?