Large gains are made few days in a year. You will most likely miss them. DCA is your friend.

If they don’t want to DCA (they really should), they should not sell for at least 4 years. It doesn’t matter when they buy: even at the absolute top, historically they will gain after 4 years.

They can also resist the urge to buy material things and stack sats instead. They don’t need another jumper or pair of Nikes. Stack those sats instead at whatever price BTC is. It would be sats they would have spent anyway, so they’ll always win.