Whether it's an advantage or a disadvantage?
everything that is being traded with money has ups and downs even a cup of coffee can go up and down like for example if coffee import encounters some troubles and the supply of coffee is decreased in the country!
so it is not really a disadvantage. and if you are a trader then it is actually an opportunity to make profit.
although if you look at bitcoin as a currency then it is not so favorable to have its price swing around so much. but a little volatility (something i hope we see in a couple of years) is ok.
Whether it's an advantage or a disadvantage?
Ups and Downs on bitcoins price is a normal thing and also to all currencies out there because there are people who do trades and buy and sell on bitcoin thats why its why the price really move up and downs. Short traders do make profits when the price tends to move down and sell it again when the price rise again.
Downs (dumps) = Good opportunity to buy cheap bitcoins using all fiat you have or half of fiat.
If you are looking for long term holding, don't look at short term ups and downs just relax with your bitcoin in safe place and keep an eye on bitcoin markets.
The advantage of Ups and Downs (swing) in bitcoin price is opportunity of profit it create for day traders.