Very simple technical analysis here. In the past month the OMX Helsinki 25 stock index has broken through resistance, and is trending in the upwards channel until proven otherwise. In the beginning of 2020, Finland's government is introducing a stock savings account with considerably better tax treatment than ever in the past. Finnish citizens are able to deposit up to 50 000 euros into the account, and trades within the account are not taxed at all, only when profits are taken out. This is a first in the history of Finland.
Finns are only able to deposit money into the account, and existing stocks can't be transferred into it. In plain English this means that no one has any option other than to buy stocks on January 1. The way I see it, going long on Helsinki is a guaranteed pump. This December pump may partly be front-running by speculators, too, but LONG is still the play here.