An "unstable market" is not normal nor good. Granted, Bitcoin is fairly unstable, but prior to recently it was pretty stable around the $230-$250 mark...
1 buyer simply see the price rise and jump in, then the next one, then another one, and then you have the first, who buys again... and another parallel reaction like this will happen in the meantime and so on..
Until it forms a bubble and crashes. It's happened plenty of times bud.
Bitcoin is an unstable currency, so random jumps in price are normal. You just have to be aware and try to foresee a bubble popping, or someone faildumping and we all lose out.
If only we had a certain day that everyone pitched in and dumped their bitcoin. That would help momentously.