If I have $ 10,000, then I will buy Bitcoin. The best option may be Bitcoin, which may currently be moving very slowly, but this does not affect it much more than in the future.
Bitcoin is a lot of people trust, and this confirms its future.
Certainly, having such an amount of money to invest right now, a lot of it will be going to bitcoin and few percentage of it will be going to altcoins with great prospect, just to have a chance to increase my bitcoin stash in the long run anyway.
I have always seen bitcoin as more of the long term thing with altcoins just being a hit and run thing for the short term, at least for the meantime, considering how they rise hugely and go back to test their historical bottom eventually and that sucks to consider holding such for the long term when I could just trade them.