4. buy 100k worth of bitcoin and keep it.
so. which one will be profitable. and why.
Buy the bitcoin. Buying miners are sunk costs and end up being depreciating assets because technology growth makes the machine obsolete over short time. If you want to buy into it you could spread your purchases out over 4 months so you're spreading out your cost basis
so. which one will be profitable. and why.
Use 50% of that money to buy Bitcoin and the remaining 50% to buy a few alternative cryptocurrencies - particularly Ripple and Ethereum.