I'm wondering if I should keep holding, or buy more?
IOTA please continue to hold, and there is still a lot of room for development in 2018. At present, the price addition does not seem to be very suitable. It is suggested that you be cautious.

Personally, I believe IOTA will still dip a little because of the overall uncertainty. I placed some buy orders at 0.00016000 BTC.
Nevertheless, if IOTA delivers what it promises the future is very bright. Possibly top 3
What do you mean by the overall uncertainty? Is it the prospect of this encrypted currency market? In any case, the future of the block chain of the Internet of things is still very bright.