It's because Avalon is selling new Bitcoin generating machines.
They only accept BTC as payment so this increases demand for BTC.
It happens every time Avalon auction kit, the previous $200 BTC was because of this also!
Do you really think that Avalon selling a few hundred BTC worth of miners really affects the value of BTC when the daily trading volume of BTC on exchanges is over 25,000 BTC?
Yes, because most of the volume is miner payments, gambling, speculation and free bitcoin dust.
Avalons are made in China, there is a big demand for them over there, it is a population of 1,400,000,000 (20% Earths Population).
They are offering a money printing machine but only accept payment in the money it prints meaning you gotta buy Bitcoins!