Bitcoin certainly has a strange fascination with the number 666, regardless if its a rally or a drop in price. I check my paranoid app every now and then and i can't count the times i've seen the price stuck at $666.
this mainly happens on stamp, but fewer times on BTCE. Not sure how would someone manipulate the market to get that figure ? unless some whale has a bot that accurately does it mathematically taking advantage of low volume and is having some fun.
either way interesting stuff