No manipulation or fraud.
Sorry, I don't see then how it could never fall. It will always have its moments the price will fall
against something.
If you can mathematically prove that this can work, if everything is transparent and decentralized, the only remaining open point is trust - you have to prove that the network is strong enough and you / your business model can work. It may take a lot of time...
Unfortunately I remain skeptic: I don't think that this is possible in real life.
The decentralized model is expensive for translation. (The more expensive the coin, the higher the commission).
Centralized - minimal fees.