Bitcoin dropped from $635 to as low as $591 in the space of 40 minutes as of 19:30pm today, a loss of ~3.6%.
The coin has since recovered slightly and is traading at $605 at the time of writing this post.
In other news Monero also suffered a loss in excess of 10.40% of its value at the time of this article, having $2 wiped off its price and is now trading at $10.90 at time of writing.