Bitcoins were worth over $1200 in December, and now they're below $600. I guess the idea is to get a bunch of suckers to buy and drive up the price, then quick dump them before they vanish into thin air.
BTW... what's the FDIC limit on insurance for them? Ah... right... $0.
There are a few fluctuations due to speculation. Most people are just accumulating and not spending, slow velocity of money means deflation which jacks up the value of bitcoin. That should start to even out as more vendors accept them.