Help me understand: If the upcoming ETF spot decision is a 'Sell the news' event, then why not sell now?

As the title says, there are two popular assumptions that I've recently come across:

• If the spot ETF will be rejected by the SEC, the price will drop.
• If the spot ETF will be approved by the SEC, then it's a "sell the news" event, and the price will drop (even if temporarily).

So if the price is going to drop anyways, why don't we see a massive sell-off today coming from the exact same people who plan to sell their bags once the ETF is approved/rejected? That is, any avalanche in price that could start by the 10th of January moments after the decision is published, could also start today.