My opinion you can pick Waves , Ethereum , Litecoin and some Dogecoin , these Altcoin the price growing slow but sure.
I would not pick Dogecoin the days of Dogecoin are long gone. Back in 2014/2015 it was big, but now it is going the way of the Dodo, sadly.
Dogecoin is just going up again and is good to transfer Bitcoins fast and cheap indirectly. But you are right, its to risky to invest into doge.
400$ is large enough to create a good portfolio of wellknown cryptos. I would take Bitcoin for half amount and the rest for wellknown altcoins like for example Ethereum, Dash, ZCash, Litecoin and so on and ICOs of promising projects with innovative or social projects like Solar DAO Coin or CareCoin. You can find many helpful infos about ICOs here in altcoin section.
So buy $200 BTC, $200 different altcoins. Hodl it for 2-3 month or longer, sell it when it's high and reinvest funds into new currencies ?