For the weekend Forex market is closed , so for the traders only cureency for trading is BTC/USD so thats why the price is going up for the weekend.
And what happend next is : the price will go skyhigh and someone will sell bunch BTC and then the price will fall down.
That's the simmple answer
So dont worry sleep tight BTC is not a bubble, price will be back in 1-2 days :)
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From @theguy1986