I would call 1% of the current supply a whale, so around 110,000 XMR.
Whale definition fluctuates with the price, if Monero shoots above $5, 0.1% is pretty much a whale
Less than .1% has the potential to make someone extremely wealthy IF Monero can achieve its objective of establishing an important privacy hub.
I predict that in 10 years .1% of Monero will either be worth close to zero or be enough to retire on. Failure may be more likely but the potential reward is so great that the risk appeals to me.