that is why it is said a million times that Market Capitalization is not something you should even look at because it is a wrong and misleading number. specially when it comes to comparison. but unfortunately nobody listens.

about rises and drops, the amount and market cap do not matter. what matters is how that amount is dumped on the market and how the order books are looking at the time of that dump.
for example if you have 100,000BTC and dump it all at once on one exchange, let say Coinbase, the price in Coinbase will drop hard. i don't have an account there to check this but lets assume it will drop to $1000, in which case market does not even react to this. because it was instantaneous and only in one exchange. i said Coinbase because it has happened before. price dropped to less than $10 last year and nothing happened in the whole market.

not lets assume that 100,000BTC is dumped on all major exchanges. that is a different story. if it can bring the price down 10% in each exchange it can cause a bigger drop specially if it is not a sudden dump but a slow unloading to keep pushing it down. something like the first time price was pushed below $10k 3-4 weeks ago.