I'd put $10k in 5 of the top 10 market cap coins or I would put $5K in all 10 top coins.
I wouldnt invest the whole nugget at one time, in case the market moves dramatically downward. never put all your value in one asset, or asset class for that measure, for this very reason.
try a system of thirds or fourths to hedge some of the risk this volatility brings to the table. go in say, 25 percent on a main (eth or btc) and 25 percent on some top 10 cap coins that are significantly cheaper, and under more active development (litecoin for example). if the price moves 20%, buy in again with the remaining 50% of your position, and you will have only experienced a 10% loss.
if you want more risk, take that second 25% allocation, and invest in lower top 20 alts, and eth tokens. way more volatility, but way more profit