Alright, you convinced me. I needed more inbound liquidity anyway.

I've bought 10k shares for each of the qualifying teams and also 10k No shares of Real Madrid. 

Even if I don't track and trade further I'll end up winning 2000 Sats. 
My total invested sats are 18k, I'll get 20k. (All in approximation)
That makes it a profit of 20% Sats if I be passive. But I won't be. I'll sell the yes shares for whatever I can for the teams I suspect not advancing towards the final on June 1. So I'll end up with much more (daggers drawn.... Sorry fingers crossed) 

Coinsreporter

Stacker_Sports

Degens' Meetup #2 — Free Sats Waiting on UEFA Champions Legue Market on Predyx

I might still do it. The thing is, the two approaches you describe are equivalent. You can buy the "no"s directly or you can shrink the "no" probabilities by buying up "yes"s on the remaining teams.

The first approach makes more sense, since they're eliminated, but it's also not as fun, because there's no more tracking and trading to do.