Well here are 4 that I predict will likely be in the top ten around that time:
Bitcoin it is essentially the reserve currency of crypto so best guess is it would remain a top contender for quite a few years.
Litecoin There is word that the developer of litecoin will be hard at work developing the blockchain for litecoin to keep up with tech and improve the coin.
Ethereum normal not classic version it has tons of dependencies that support it and it came close to over shadowing bitcoins market cap at one point first time in the history of crypto.
Below is the last one because I believe this will be the sling shot coin that everyone will kick themselves for not investing in.
Particl
As far as the other coins available it is really difficult to say.
Dash Aka DarkCoin in its younger days has been a pretty interesting coin to watch rise.
Monero is another interesting coin as well as Zcash.
I hold hope still for Dogecoin it was a top 10 coin for years and its transmission is rather speedy. The other interesting thing is the projects Devs are devs that work on Bitcoin as well. It was the most profitable coin over time for me pickup when dirt chip dump after 100 -400 % gains then wait for dump to level and gain more coins rinse and repeat.
Verge formerly dogecoin dark has a fairly active developer so hard telling where that project will go but I commend his persistence if he continues he will win some more investment.
Slightly possible that Neo Aka Antshares could hold in there as well.
Another big underdog right now I am interested to see how it plays out is cloak coin.
Clams is a fairly rare investment it wouldn’t take a miracle for that to go moonward as well.
There you have it I gave away all of my personal secrets I’ve been kinda holding with the exception of Particl this one for me the utility is everything I am looking for in a coin not to even brag it up if you truly understand just the fact that it is rare and anonymous is interesting. Now you factor in MAD escorow, DAPS, The Market, Security Through Staking Rather than Mining which means countries like Venezuela, won’t hit people for “stealing electricity” Not to mention there is now a unlock for staking only method. The last thing to cap things off is the ability to exchange 25+ coins which will be added to function at first with Shapeshift integration than moving to its own version. I think it is kind of hard for me to keep this one a secret it is like knowing your good friend is getting married or having a kid type thing you want to tell everyone even though you are not “supposed to” lol!