I dont think that their is any investment option which gives you good return with security, it is better that you can do some trading in alt coin before that you first get details about the coin and then start to trade
Altcoin trading is far more risky than doing direct bitcoin exchange from usd. But when doing trades just remember to do selling coins only if you make profit out of your buying rate. With the expected hype that halving will bring, doing exchange trades of btc will really be more interesting.
Bitcoin trading is always better then alt coin trading, as if you buy now and hold till the halving then you can earn great amount of profits by selling at the time of halving.
Actually no need to wait for halving. Recently we came up with the price movement with a margin of $30-$50. We can make profits here rather than to wait for halving. We can have our coins increase the quantity too if we managed to get the advantage of this movement so still we can enjoy the halving effect.