Buy and hold, dont waste time trading if you're not experienced. You will waste time watching charts all day and could potentially lose money. BTC can go down like it just did but if you look monthly it always gains a few %.
Indeed, I would not have time for exchanging and rate following, however buying and holding is very slow and unknown process with no guarantees such as 100% profit in certain period of time. But what here im saying is that if you can invest, you'll have your coins in your control, but in end of the day you are getting your coins back + % from investment. So think about it if i bought 1 btc and then waited 2 years it to grow until lets say 1,5k so what i did was 500 dollars in profit in 2 years? Meanwhile If I was investing and getting additional % then this would make it much more profitable. There is a possibility you will get scammed if you dont find any trustworthy firm in your opinion if you dont try. Nowadays there are hundreds scam sites and stuff and these sites damage popularity for the real sites because people lose respect and trust into those sites and they just try to do everything by themselves. If I was gonna trust a firm with such investment methods id try of course not put 100 btc but at least 1 or a minimum they accept. I believe crypto money investment possibilities are out there somewhere, at this time of crypto growth it just must be because its just best thing ever could be.
Don't forget you have to consider 2 things while trading like that:
1. You can make a bad judgement like those guys selling below $600 two days ago. You buy 1 for 1000, at 1200 decide you got enough profit and sell, next day it goes up to 1300 what do you do, wait for it to go down or buy back at 1300? Whatever you do you just lost compared to a guy who held.
2. There are trading fees so the more you trade the more you pay to the exchange.
A trader buying low and selling high will outperform a holder but he also invests a lot of time and nerves in the process.