At what price levels will Bitcoin hodlers sell a significant part of their coins?
I honestly strongly believe in this technology at the moment so much, that I wouldn't sell any of my Bitcoins even if we hit 10,000. That is how I voted!
If you won't sell your bitcoin at any price below 10,000 then you will probably not even buy anything with it as payment processors like coinbase convert it to USD instantly. Then how will just holding on to the bitcoins ever benefit you, if the price never actually goes over 10K ?
I am actually buying with Bitcoin very often but as soon as I buy, I also buy the same amount of the exchange. So at the end of the day, I am at the same balance or even ahead since shopping for Bitcoin nowadays gives you very ofteh great discounts (read purse.io for example).
Now why am I doing something so complicated you might ask? Well I decided that I will support the network in this way by transacting and not just hoarding, since I think that actual transacting is very important for the adoption at the moment. And at the end, because of the discounts, I often make small earnings as well.
Now to answer second part of your question, this way of holding will benefit me greatly since I believe that 1 BTC will be worth much more than $10,000 in the future. When this happens, I will see what I will do!