Seems like this is something we don't think about or at least think about in the right way. We see the forest, no trees (or however that goes).

I could

• Install a virus on your phone that hijacks the price ticker you use.
• Hijack the provider you use (probably also on you phone, probably also part of the very same app, e.g. metamask + metamask price ticker [widget?]) to send whatever coins you're dumping into my wallet.
• I could do this with a zillion phones at once, each time just taking a sip of ether. Until someone notices. And I can do practically infinity things to evade detection. Of course you're exiting this doomed currency. Don't want to be around for the explosion. Nosiree.

That doesn't seem like a very tall order, given the incentives involved.