Both are good to invest because you will buy it in a cheap price so grab the opportunity. Although the market is always fluctuating is good to buy now both altcoin and bitcoin.
I think at this point the long-term investment is completely wrong, you can see that the market is bearish in the long run, so to be able to successfully trade at this time is very difficult , bitcoin prices will likely continue to fall sharply at any time. So I believe you should only invest in short-term investments in bitcoin to minimize risk.