Usually they recommend you to diversify your investment, so you avoid losses.
But as a real approach, having $1.5k, would you invest in how many cryptocurrencies ?
What if I invest little by little, only in Bitcoin, would that work as well ?
Its all with your own choice or preference because the ideal cryptocurrencies is having a good altcoins that will become a big source of profits in coming months. I, around 10-20 altcoins for that amount and here if you want it only in bitcoins diversify your bitcoins in different safe wallets to protect it from losses and any damage that we cant assure.