Here is my own investment advice but not to be taken very seriously because anything can happen in crypto space...
I think the best altcoins you can invest on in crypto space are bitcoin forks, they are very responsive to bitcoin movement and their All Time High is very good too, one for thing is these coins have their halving coming this very year as well
1. Bitcoin Gold
2. Bitcoin Diamond
3. Bitcoin Cash
4. Lightening Bitcoin
5. Bitcoin Private
These coins have their use cases and they offer better performance compare to their king ( Bitcoin ) and their team are very active as well, looking at the past chart of Jan 2018 these coins ATH are massive, buying now means buying at extremely cheap price, they are jumpy, active , responsive to Bitcoin Movement and their Halving is happening this 2020 as well.
Please do not hesitate to do your own research and go through their whitepapers, these are no new projects, they have proven their existence already, thank you
I don't think like that because do you remember in 2017 when BCD etc bitcoin forks seemed to be manipulating the market and the price suddenly dropped? it was intentional
so in my opinion bitcoin fork is not a good coin to be used for long term trading but if you look at it from the point of view of transaction cost performance etc. maybe bitcoin fork is definitely better than bitcoin