I do not understand why the price continues to be always negative
a) Because of the upcoming Bitcoin fork and the overall movement of $$ away from alts until that happens; and b) because crypto has almost no attention span and Ark is a 'slow and steady' sort of project. Look at it over a longer time-frame, though, and you'll see that Ark has been developing nicely. Take advantage of the lower prices, don't micro-manage, and enjoy the results over the long run.
How works pos?
I am going to recycle a previous post of mine to answer this:
Delegated Proof of Stake (DPoS) isn't really that weird--it just seems confusing at first. Ark is also not the only asset that uses it; BitShares and Shift are two others.
The point is that instead of everyone staking their own Ark, they instead add the 'weight' of their Ark together into pools that are run by specific 'delegates'. Only delegates can create new blocks on the network, and they are rewarded for this service. As an Ark holder, you use your Ark to vote for a delegate of your choice. Anyone can attempt to become a delegate, but of course you, as an Ark holder, will vote for a delegate that offers more benefits than the others. Mostly, these benefits take the form of redistributed rewards; i.e., the delegate promises to return X% of their rewards back to voters. But there are other considerations: maybe a delegate also proposes to use some % of their rewards for advertising that will benefit Ark, or maybe they propose to use some % to build and maintain a super-awesome server that will improve the network. So, rewards are the main reason people vote for one delegate over another, but they are not the only reason.
Only the 51 delegates with the most votes at any given time receive rewards. As soon as they fall out of the top 51, they receive nothing--and of course the people voting for them receive nothing also. So there is an incentive for delegates to always improve their service to the network in order to stay in favour with voters.
Think of it this way: instead of paying for a computer and electricity (and your time) to stake your own coins in your own wallet, you are contributing the weight of your Ark by voting for a delegate, and paying them a small fee, to do it for you. The democratic nature of the system means that only reliable, trustworthy delegates will remain in the top 51, ensuring network health. The system is also more favourable to small holders, for whom the cost/benefit of staking might otherwise be prohibitive.
If you want more detailed info, check out:
https://steemit.com/dpos/@dantheman/dpos-consensus-algorithm-this-missing-white-paper
...of course, if your question was more general, as in, how does Proof-of-Stake work, as opposed to how does Ark's system work, then something like the Wikipedia entry may be more useful for you:
https://en.wikipedia.org/wiki/Proof-of-stake
