This is my personal theory, and please do your own research and due diligence when it comes to your own financials.
We've seen Bitcoin on a bull rally for the past 7 days, and if we don't count some turbulence a week ago, we've been going up pretty much for two weeks. Alt coins however, and even stable coins like Ethereum and Litecoin, has been slaughtered.
Why? Because people want "free" Bitcoin. Last fork a lot of people, my self included was a taken a little bit off guard with the fork. Some had their Bitcoins on exchanges, and for all of us it was a great event that forced us to learn more about how Crypto Currencies works. I think a lot of people fail to see the positive effects all this technical stuff has. To own your own money requires a lot responsibility. You must constantly stay updated on the technology and gradually learn more.
With this Fork, even if it is said to be much less significant (some even call Bitcoin Gold a hoax) even more people are forced to educate themselves. More people gain more knowledge in the BlockChain technology. Which is of course great.
Now - after the fork, it is expected that a lot of people will sell their Bitcoin Gold fast. We will probably see a pump'n dump, like we saw with Bitcoin Cash.
This money will undoubtedly flow into Alt Coins. "Free" money that people feel they can gamble with.
I am almost certain in my mind that we will see a huge surge in Alt Coins after the fork. That being said, we could still see more drop in prices, and even though I have bought a little bit of Alt Coins in this latest drop, I am afraid it could drop more short term.
Long term however, you should not (in my opinion) be afraid. We are only seeing the beginning, and at this point it is all about positioning yourself in an emerging market. I own mostly Bitcoin, Ethereum, Litecoin and Steem. But I also do own 30 other Alt Coins. All of them are for hodling 10 years +. If just one or two survives and becomes the next Google or Apple or Facebook it will rise 100,000% or more.