Wait for XMR to crash and buy the dip, then wait for the next pump and you'll double your money.
i don't think xmr would rise much again like before, it will like ethereum after the price spike high then would play at same range price.
yeah no problem to invest in XMR or other altcoin but you should know that investing in altcoin is a risky thing. do not hold your altcoin too long because it will be at risk and do not allocate too much on investment altcoin. you have to set it up and have a plan with it
Right now, investing in XMR for a short term or trading is a good way because the trend is almost predictable, we sometimes see the price fall back hard and then pump again and that only happens in less than an hour and I think if you invest that $100,000 you can safely double that in a month.
Right now he do not need to invest in any altcoin and any scheme, as the price of bitcoin is increase and it itself is a good investment, it is pretty sure that in a few months he will double up his money with bitcoin. so just put them in bitcoin.