should it be invested in bitcoin and hold?
Yes invest to bitcoin and hold, some will say that don't fully invest that $100k to bitcoin but for me that's the best investment that you can earn quickly.
The movement of bitcoin's price is very fast so you can also earn fast with that big investment.
should it be invested in alt coins?
Some will also say that you have to diversify your capital to different alt coins and not only to bitcoin and if you think that you are comfortable to do that, do it.