The second stimulus checks whether it's 600$ (70% probability) or 2000$ (30%) is something that shouldn't be ignored by us. Mnuchin tweeted on Dec 29th that the checks could begin arriving in banks account "as early as tonight". Paper checks will begin to be mailed on Dec 30th.
Looking at TSLA & Bitcoin price action today, one can assume that some of the money is going directly to Robin hoods accounts.
In the case of TSLA, where the valuation doesn't have any connection with reality, the short sellers should be aware of the train that is coming towards them. (I actually have bear put spreads, but almost paid the full penalty already for betting against Musk).
As far as the Bitcoin is concerned, you actually can't give it a fair value, so no one will dare shorting it. So it's like a super train with no obstacles. When everyone just can't wait for a pullback so that they can go back in, it never comes.
If Elon Musk will buy Bitcoin too for TSLA treasury, like M. Saylor did for MSTR, then no one will dare to short TSLA too :)
If I had to bet, January effect is not something we need to be surprised of in the momentum winners of 2020.
Happy new year