This is anything but a joke.

The price of bitcoin is set at the margin, so it isn't as if every bitcoin needs to be purchased at 600k or 10,000k.  Certainly not every coin is for sale.   If there are 500,000 coins for sale between here and 10,000k you you don't need that much demand to propel it that high.  Say the average price per bitcoin between here and 10,000k is $600,000, that would be "only" $300 Billion in additional investments.  If 1 million coins were for sale, it would double.  If 6 million coins were for sale and the average was still $600,000, it would be $3 trillion in new investment, but nowhere near $10,000,000 * $20,000,000.

Back at $1 people were saying $100 or $1000, let alone $50k was impossible - not everyone of course. 

So is it possible?  Definitely, it just depends on supply at each point and demand at each point.  If everyone with bitcoin refused to sell below $10,000,000, the price would go there since people might want to own 0.00000001 or whatever.

Is it likely?  That's another question. 
Is it likely any time soon?  That too is another question.