Then who needs escrow?  Unless you are very close to someone, it is foolish to expect them to behave to a standard of your mind.  One is rarely well advised to assume even that an internet counterparty intends to hold to their commitments, and insane to expect them to hold to restraints to which they have not agreed.  Honor is highly idiosyncratic, above and beyond being cultural, and extreme diversity of idiom and culture is to be expected in a global community.

Certainly you could easily drive the market to 435, in a matter of a few minutes work.  Would it even be manipulation if you had intended to put on a big short anyhow?