You can do both...and adapt a trick from pro investors. It's called "repositioning."
Start off with, say half in Bitcoin and the other half in Litecoin (Pick whatever allocation you like, but 50%/50% makes this illustration easier.)
Then, pick a fixed day in the month - say, the first of each month.
On that day, calculate the BTC value of your litecoin.
- If that value is more than your BTC holdings, sell enough Litecoin to make the values equal.
- If that value is less than your BTC, buy enough Litecoin to make the values equal.
In either case, the values of each are back to even-steven after you reposition.
The trick here is to buy a little Litecoin if BTC is outrunning it, and vice versa if LTC is outrunning Bitcoin. This way, if BTC benefits from a pump and LTC goes into a mega-pump, you'll sell some LTC and bank profits when the LTC market is manic. And vice-versa if the LTC market is depressed. If the old saw about Litecoin being leveraged is true, you'll make more this way than if you just passively HODL.