What would be the most probable reaction from the crowds? How could I edge aginst this? I am looking for answers based on previous analogous situations in economics or finance (big surprise in something thought robust).
Your hedge against this would be to short Bitcoin. If this ever happens to the Satoshi million (a wallet that is supposedly dormant, dead and does not have anyone with control of the key), it signifies that it could happen to anyone no matter how secure they are, and therefore creates a genuine security reason to not hold bitcoin - and if it happened to the wallet holding 1/21 of the entire supply, the market would enter panic before that 1,000,000 could even start to be sold, let alone the effect it would have if it were to be sold on-market.
However an interesting thing is that the original 1,000,000 BTC is a mere $100,000,000,000...I say mere as there are institutions who would probably snap up the opportunity to buy the original 1,000,000 BTC from Satoshi, not just due to its value but due to its significance. Heck, MSTR wanted to raise $10b to buy bitcoin on-market and BlackRock + Coinbase both have almost 1,000,000 BTC each as well...so maybe the market effect wouldn't even be that devastating in the long run, and the initial 1,000,000 coins going on market themselves wouldn't kill Bitcoin...but the event of them being hacked and what that signifies could.