yes the graphs definitely look pretty similar but I can't think of any reasons why they might be related. They are 2 different types of investments with probably different markets as well. Maybe think of this in a practical sense and it will be easier to explain. Bitcoin is a fairly new cryptocurrency that has a new market, is decentralized and also can be used to make purchases online. While gold is a rare metal, that is used for fashion and also one of the oldest investment options out there, it is super stable and is on a steady climb up, while bitcoin just feel around 1000 USD in the span of one week. Both investment options, but they are still totally different things, and probably have no relation to each other and
what you have notice in the charts are mere coincidences. After all, there will always be a high and low movement in any market, be it bitcoin or gold or silver or foreign exchange rates, etc. These are affected by a different set of unique circumstances because they are independent from each othe.