This means that Satoshi's BTC (~1mio.) are potentially liquid which would mean a gigantic influx of fresh bitcoins.
It's quite plausible that any movement of these old wallets would crash the Bitcoin price for quite a while.
There's no way to absolutely sure that the keys are gone and inaccessible permanently.
The daily volume of BTC is somewhere between $3bn and $25bn depending on how much fake volume is being reported by shady exchanges. And it might be far less because that will include things like transfers between wallets, payments and exchanges from and to fiat currencies and other cryptos.
But even at the high figure there Satoshi's coins are worth twice as much as is traded every day, meaning that selling 10% of their stash would be between 20% to 150% of everything traded in a day and would tank the price drastically. Just a few days ago the price of BTC dropped 23% in one day after a mining pool sold off only 3,633 coins in one go:
https://www.cityam.com/bitcoin-price-crashed-here-is-what-co...
Satoshi has 300 times as many coins as that...
Imagine if suddenly someone found 100 000 metric tons of gold and wanted to sell fast. It would saturate the market and the price would plummet.
Same would happen if Satoshi wanted to quickly sell 50 billion of coins.
Yes theoretically it is 1T, but practically much lower...
$1T is the market cap when each bitcoin is trading at ~$52k, but if $50B were sold over a short period of time, it would likely drop the price to $25k or less as the buy orders would all get eaten up
