Here are some suggestions : ETH, Ripple, Bitcoin cash and Litecoin. None of these coins will be in negative if you hold for 3 months or more. If you diversify i all of these , you will be safe as well.
I would have to agree that top altcoins are few of the best coins to invest this time as Bitcoin and Crypto Market has been surging and recovering from the major crypto crisis that we experienced since 3rd week of January this year.
investing Ethereum, NEO, Ripple, Cardano, Tron, Stellar and other promising top altcoins in coinmarketcap.com will offer higher profits and rewards than new listed altcoins.