Very proven, Yes. Holding bitcoin for longtime proves to be one of the best ways to grow money we have. Very much compared to interest given by bank.
I think so. But I am leaning towards a YES! I have known this colleague of mine who bought Bitcoins years ago just for NBA betting. He let his Bitcoins sleep for years since he already stopped online betting. Now, or years later, look at the value of his Bitcoins! He is a multi-millionaire just by doing nothing! So I guess if you have the means to just buy Bitcoins and let it sleep for years.. Then who knows, one day you wake up being a multi-millionaire yourself!